diff --git a/platforms/iOS/vm/OSX/sqSqueakOSXCGView.m b/platforms/iOS/vm/OSX/sqSqueakOSXCGView.m
index 2ade6de334..a2a5307741 100644
--- a/platforms/iOS/vm/OSX/sqSqueakOSXCGView.m
+++ b/platforms/iOS/vm/OSX/sqSqueakOSXCGView.m
@@ -51,6 +51,7 @@ Some of this code was funded via a grant from the European Smalltalk User Group
 
 extern SqueakOSXAppDelegate *gDelegateApp;
 extern struct	VirtualMachine* interpreterProxy;
+extern sqInt cannotDeferDisplayUpdates;
 
 static NSString *stringWithCharacter(unichar character) {
 	return [NSString stringWithCharacters: &character length: 1];
@@ -75,7 +76,9 @@ - (void)awakeFromNib {
 - (void)initialize {
 
     // NSLog(@"initialize %@", NSStringFromRect([self frame]));
-
+	
+	cannotDeferDisplayUpdates = 1;
+	
 	[self setAutoresizingMask:NSViewWidthSizable | NSViewHeightSizable];
     [self setAutoresizesSubviews:YES];
 
diff --git a/platforms/iOS/vm/OSX/sqSqueakOSXMetalView.m b/platforms/iOS/vm/OSX/sqSqueakOSXMetalView.m
index 0a91abc502..c4cc4e2438 100644
--- a/platforms/iOS/vm/OSX/sqSqueakOSXMetalView.m
+++ b/platforms/iOS/vm/OSX/sqSqueakOSXMetalView.m
@@ -50,6 +50,7 @@
 extern struct VirtualMachine* interpreterProxy;
 
 static sqSqueakOSXMetalView *mainMetalView;
+extern sqInt cannotDeferDisplayUpdates;
 
 #define STRINGIFY_SHADER(src) #src
 static const char *squeakMainShadersSrc =
@@ -145,6 +146,7 @@ - (void)initialize {
 	
 	self.paused = YES;
 	self.enableSetNeedsDisplay = YES;
+	cannotDeferDisplayUpdates = 1;
 	
 	NSMutableArray *drawingLayers = [NSMutableArray arrayWithCapacity: MAX_NUMBER_OF_EXTRA_LAYERS];
 	for(int i = 0; i < MAX_NUMBER_OF_EXTRA_LAYERS; ++i) {
diff --git a/src/spur32.cog.lowcode/cointerp.c b/src/spur32.cog.lowcode/cointerp.c
index ad3390349d..5fa0ba8cc2 100644
--- a/src/spur32.cog.lowcode/cointerp.c
+++ b/src/spur32.cog.lowcode/cointerp.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2669,8 +2669,9 @@ sqInt sendWheelEvents;
 sqInt suppressHeartbeatFlag;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 char expensiveAsserts = 0;
 int (*showSurfaceFn)(sqIntptr_t, int, int, int, int);
@@ -95544,6 +95545,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur32.cog.lowcode/cointerp.h b/src/spur32.cog.lowcode/cointerp.h
index f77e93277f..5726b93409 100644
--- a/src/spur32.cog.lowcode/cointerp.h
+++ b/src/spur32.cog.lowcode/cointerp.h
@@ -1,5 +1,5 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
 
 
@@ -336,6 +336,7 @@ extern sqInt ultimateLiteralOf(sqInt aMethodOop);
 extern sqInt breakLookupClassTag;
 extern char * breakSelector;
 extern sqInt breakSelectorLength ;
+extern sqInt cannotDeferDisplayUpdates;
 extern sqInt checkedPluginName;
 extern sqInt checkForLeaks;
 extern sqInt debugCallbackInvokes;
diff --git a/src/spur32.cog.lowcode/gcc3x-cointerp.c b/src/spur32.cog.lowcode/gcc3x-cointerp.c
index c899315248..174e064347 100644
--- a/src/spur32.cog.lowcode/gcc3x-cointerp.c
+++ b/src/spur32.cog.lowcode/gcc3x-cointerp.c
@@ -2,11 +2,11 @@
 
 
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2672,8 +2672,9 @@ sqInt sendWheelEvents;
 sqInt suppressHeartbeatFlag;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 char expensiveAsserts = 0;
 int (*showSurfaceFn)(sqIntptr_t, int, int, int, int);
@@ -95553,6 +95554,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur32.cog/cointerp.c b/src/spur32.cog/cointerp.c
index d960559db2..4e18246bf0 100644
--- a/src/spur32.cog/cointerp.c
+++ b/src/spur32.cog/cointerp.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2644,8 +2644,9 @@ sqInt sendWheelEvents;
 sqInt suppressHeartbeatFlag;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 char expensiveAsserts = 0;
 int (*showSurfaceFn)(sqIntptr_t, int, int, int, int);
@@ -75477,6 +75478,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur32.cog/cointerp.h b/src/spur32.cog/cointerp.h
index 7f4af01f5a..a6c1a4dbc8 100644
--- a/src/spur32.cog/cointerp.h
+++ b/src/spur32.cog/cointerp.h
@@ -1,5 +1,5 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
 
 
@@ -331,6 +331,7 @@ extern sqInt ultimateLiteralOf(sqInt aMethodOop);
 extern sqInt breakLookupClassTag;
 extern char * breakSelector;
 extern sqInt breakSelectorLength ;
+extern sqInt cannotDeferDisplayUpdates;
 extern sqInt checkedPluginName;
 extern sqInt checkForLeaks;
 extern sqInt debugCallbackInvokes;
diff --git a/src/spur32.cog/cointerpmt.c b/src/spur32.cog/cointerpmt.c
index 9b6920b7c3..86f9f72fb2 100644
--- a/src/spur32.cog/cointerpmt.c
+++ b/src/spur32.cog/cointerpmt.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreterMT VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreterMT VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreterMT VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreterMT VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2737,8 +2737,9 @@ sqInt suppressHeartbeatFlag;
 sqInt willNotThreadWarnCount;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog MT VM [CoInterpreterMT VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog MT VM [CoInterpreterMT VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 char expensiveAsserts = 0;
 int (*showSurfaceFn)(sqIntptr_t, int, int, int, int);
@@ -77612,6 +77613,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur32.cog/cointerpmt.h b/src/spur32.cog/cointerpmt.h
index 8b3c3506bd..1224070e8c 100644
--- a/src/spur32.cog/cointerpmt.h
+++ b/src/spur32.cog/cointerpmt.h
@@ -1,5 +1,5 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
 
 
@@ -333,6 +333,7 @@ extern sqInt ultimateLiteralOf(sqInt aMethodOop);
 extern sqInt breakLookupClassTag;
 extern char * breakSelector;
 extern sqInt breakSelectorLength ;
+extern sqInt cannotDeferDisplayUpdates;
 extern sqInt checkedPluginName;
 extern sqInt checkForLeaks;
 extern sqInt debugCallbackInvokes;
diff --git a/src/spur32.cog/gcc3x-cointerp.c b/src/spur32.cog/gcc3x-cointerp.c
index 8d74194aeb..14a740f741 100644
--- a/src/spur32.cog/gcc3x-cointerp.c
+++ b/src/spur32.cog/gcc3x-cointerp.c
@@ -2,11 +2,11 @@
 
 
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2647,8 +2647,9 @@ sqInt sendWheelEvents;
 sqInt suppressHeartbeatFlag;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 char expensiveAsserts = 0;
 int (*showSurfaceFn)(sqIntptr_t, int, int, int, int);
@@ -75486,6 +75487,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur32.cog/gcc3x-cointerpmt.c b/src/spur32.cog/gcc3x-cointerpmt.c
index bfc12bbc8b..507baec99d 100644
--- a/src/spur32.cog/gcc3x-cointerpmt.c
+++ b/src/spur32.cog/gcc3x-cointerpmt.c
@@ -2,11 +2,11 @@
 
 
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreterMT VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreterMT VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreterMT VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreterMT VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2740,8 +2740,9 @@ sqInt suppressHeartbeatFlag;
 sqInt willNotThreadWarnCount;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog MT VM [CoInterpreterMT VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog MT VM [CoInterpreterMT VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 char expensiveAsserts = 0;
 int (*showSurfaceFn)(sqIntptr_t, int, int, int, int);
@@ -77621,6 +77622,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur32.sista/cointerp.c b/src/spur32.sista/cointerp.c
index 9b059b8939..39c65269e7 100644
--- a/src/spur32.sista/cointerp.c
+++ b/src/spur32.sista/cointerp.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2659,8 +2659,9 @@ sqInt sendWheelEvents;
 sqInt suppressHeartbeatFlag;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 char expensiveAsserts = 0;
 int (*showSurfaceFn)(sqIntptr_t, int, int, int, int);
@@ -78550,6 +78551,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur32.sista/cointerp.h b/src/spur32.sista/cointerp.h
index f65b16986b..1147102cd7 100644
--- a/src/spur32.sista/cointerp.h
+++ b/src/spur32.sista/cointerp.h
@@ -1,5 +1,5 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
 
 
@@ -335,6 +335,7 @@ extern sqInt ultimateLiteralOf(sqInt aMethodOop);
 extern sqInt breakLookupClassTag;
 extern char * breakSelector;
 extern sqInt breakSelectorLength ;
+extern sqInt cannotDeferDisplayUpdates;
 extern sqInt checkedPluginName;
 extern sqInt checkForLeaks;
 extern sqInt debugCallbackInvokes;
diff --git a/src/spur32.sista/gcc3x-cointerp.c b/src/spur32.sista/gcc3x-cointerp.c
index de832f76c3..b1164e3d32 100644
--- a/src/spur32.sista/gcc3x-cointerp.c
+++ b/src/spur32.sista/gcc3x-cointerp.c
@@ -2,11 +2,11 @@
 
 
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2662,8 +2662,9 @@ sqInt sendWheelEvents;
 sqInt suppressHeartbeatFlag;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 char expensiveAsserts = 0;
 int (*showSurfaceFn)(sqIntptr_t, int, int, int, int);
@@ -78559,6 +78560,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur32.stack.lowcode/gcc3x-interp.c b/src/spur32.stack.lowcode/gcc3x-interp.c
index 48a176cfd7..bca9685a92 100644
--- a/src/spur32.stack.lowcode/gcc3x-interp.c
+++ b/src/spur32.stack.lowcode/gcc3x-interp.c
@@ -2,11 +2,11 @@
 
 
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2383,8 +2383,9 @@ sqInt sendWheelEvents;
 char * breakSelector;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt suppressHeartbeatFlag;
 char expensiveAsserts = 0;
 int (*showSurfaceFn)(sqIntptr_t, int, int, int, int);
@@ -78776,6 +78777,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur32.stack.lowcode/interp.c b/src/spur32.stack.lowcode/interp.c
index 0b10e93d95..5dc6e7bd87 100644
--- a/src/spur32.stack.lowcode/interp.c
+++ b/src/spur32.stack.lowcode/interp.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2380,8 +2380,9 @@ sqInt sendWheelEvents;
 char * breakSelector;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt suppressHeartbeatFlag;
 char expensiveAsserts = 0;
 int (*showSurfaceFn)(sqIntptr_t, int, int, int, int);
@@ -78767,6 +78768,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur32.stack/gcc3x-interp.c b/src/spur32.stack/gcc3x-interp.c
index d048335944..87f14262c7 100644
--- a/src/spur32.stack/gcc3x-interp.c
+++ b/src/spur32.stack/gcc3x-interp.c
@@ -2,11 +2,11 @@
 
 
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2358,8 +2358,9 @@ sqInt sendWheelEvents;
 char * breakSelector;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt suppressHeartbeatFlag;
 char expensiveAsserts = 0;
 int (*showSurfaceFn)(sqIntptr_t, int, int, int, int);
@@ -65566,6 +65567,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur32.stack/interp.c b/src/spur32.stack/interp.c
index 682124f3c8..5c5f3d663f 100644
--- a/src/spur32.stack/interp.c
+++ b/src/spur32.stack/interp.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2355,8 +2355,9 @@ sqInt sendWheelEvents;
 char * breakSelector;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt suppressHeartbeatFlag;
 char expensiveAsserts = 0;
 int (*showSurfaceFn)(sqIntptr_t, int, int, int, int);
@@ -65557,6 +65558,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur32.stack/validImage.c b/src/spur32.stack/validImage.c
index 88fcf282a5..c9a6dd9b92 100644
--- a/src/spur32.stack/validImage.c
+++ b/src/spur32.stack/validImage.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	ImageLeakChecker VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	ImageLeakChecker VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "ImageLeakChecker VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "ImageLeakChecker VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -927,6 +927,7 @@ sqInt sendWheelEvents;
 sqInt breakLookupClassTag;
 char * breakSelector;
 sqInt breakSelectorLength = MinSmallInteger;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackPath;
@@ -943,7 +944,7 @@ sqInt extraVMMemory;
 sqInt ffiExceptionResponse;
 sqInt inIOProcessEvents;
 struct VirtualMachine* interpreterProxy;
-const char *interpreterVersion = "Open Smalltalk ImageChecker VM [ImageLeakChecker VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk ImageChecker VM [ImageLeakChecker VMMaker.oscog-mt.3184]";
 sqInt suppressHeartbeatFlag;
 char expensiveAsserts = 0;
 volatile int sendTrace;
diff --git a/src/spur64.cog.lowcode/cointerp.c b/src/spur64.cog.lowcode/cointerp.c
index e999c9cd41..50a8ee3181 100644
--- a/src/spur64.cog.lowcode/cointerp.c
+++ b/src/spur64.cog.lowcode/cointerp.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2687,8 +2687,9 @@ sqInt sendWheelEvents;
 sqInt suppressHeartbeatFlag;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 int displayWidth;
 int displayDepth;
@@ -96393,6 +96394,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur64.cog.lowcode/cointerp.h b/src/spur64.cog.lowcode/cointerp.h
index 1d4c7ad3a4..67f8ab18c3 100644
--- a/src/spur64.cog.lowcode/cointerp.h
+++ b/src/spur64.cog.lowcode/cointerp.h
@@ -1,5 +1,5 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
 
 
@@ -338,6 +338,7 @@ extern sqInt ultimateLiteralOf(sqInt aMethodOop);
 extern sqInt breakLookupClassTag;
 extern char * breakSelector;
 extern sqInt breakSelectorLength ;
+extern sqInt cannotDeferDisplayUpdates;
 extern sqInt checkedPluginName;
 extern sqInt checkForLeaks;
 extern sqInt debugCallbackInvokes;
diff --git a/src/spur64.cog.lowcode/gcc3x-cointerp.c b/src/spur64.cog.lowcode/gcc3x-cointerp.c
index 447e50edb7..6c8bdcf72c 100644
--- a/src/spur64.cog.lowcode/gcc3x-cointerp.c
+++ b/src/spur64.cog.lowcode/gcc3x-cointerp.c
@@ -2,11 +2,11 @@
 
 
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2690,8 +2690,9 @@ sqInt sendWheelEvents;
 sqInt suppressHeartbeatFlag;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 int displayWidth;
 int displayDepth;
@@ -96402,6 +96403,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur64.cog/cointerp.c b/src/spur64.cog/cointerp.c
index 06b5213669..a642157388 100644
--- a/src/spur64.cog/cointerp.c
+++ b/src/spur64.cog/cointerp.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2663,8 +2663,9 @@ sqInt sendWheelEvents;
 sqInt suppressHeartbeatFlag;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 int displayWidth;
 int displayDepth;
@@ -76538,6 +76539,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur64.cog/cointerp.h b/src/spur64.cog/cointerp.h
index 720e3c1c9c..e6296fb75f 100644
--- a/src/spur64.cog/cointerp.h
+++ b/src/spur64.cog/cointerp.h
@@ -1,5 +1,5 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
 
 
@@ -333,6 +333,7 @@ extern sqInt ultimateLiteralOf(sqInt aMethodOop);
 extern sqInt breakLookupClassTag;
 extern char * breakSelector;
 extern sqInt breakSelectorLength ;
+extern sqInt cannotDeferDisplayUpdates;
 extern sqInt checkedPluginName;
 extern sqInt checkForLeaks;
 extern sqInt debugCallbackInvokes;
diff --git a/src/spur64.cog/cointerpmt.c b/src/spur64.cog/cointerpmt.c
index 8db2048e5c..febea14a6f 100644
--- a/src/spur64.cog/cointerpmt.c
+++ b/src/spur64.cog/cointerpmt.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreterMT VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreterMT VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreterMT VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreterMT VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2756,8 +2756,9 @@ sqInt suppressHeartbeatFlag;
 sqInt willNotThreadWarnCount;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog MT VM [CoInterpreterMT VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog MT VM [CoInterpreterMT VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 int displayWidth;
 int displayDepth;
@@ -78673,6 +78674,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur64.cog/cointerpmt.h b/src/spur64.cog/cointerpmt.h
index a64dffc33a..21d0c6fd9c 100644
--- a/src/spur64.cog/cointerpmt.h
+++ b/src/spur64.cog/cointerpmt.h
@@ -1,5 +1,5 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
 
 
@@ -335,6 +335,7 @@ extern sqInt ultimateLiteralOf(sqInt aMethodOop);
 extern sqInt breakLookupClassTag;
 extern char * breakSelector;
 extern sqInt breakSelectorLength ;
+extern sqInt cannotDeferDisplayUpdates;
 extern sqInt checkedPluginName;
 extern sqInt checkForLeaks;
 extern sqInt debugCallbackInvokes;
diff --git a/src/spur64.cog/gcc3x-cointerp.c b/src/spur64.cog/gcc3x-cointerp.c
index e87327f512..4381df8ab8 100644
--- a/src/spur64.cog/gcc3x-cointerp.c
+++ b/src/spur64.cog/gcc3x-cointerp.c
@@ -2,11 +2,11 @@
 
 
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2666,8 +2666,9 @@ sqInt sendWheelEvents;
 sqInt suppressHeartbeatFlag;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 int displayWidth;
 int displayDepth;
@@ -76547,6 +76548,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur64.cog/gcc3x-cointerpmt.c b/src/spur64.cog/gcc3x-cointerpmt.c
index 77da3a7616..6dfe416877 100644
--- a/src/spur64.cog/gcc3x-cointerpmt.c
+++ b/src/spur64.cog/gcc3x-cointerpmt.c
@@ -2,11 +2,11 @@
 
 
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreterMT VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreterMT VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreterMT VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreterMT VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2759,8 +2759,9 @@ sqInt suppressHeartbeatFlag;
 sqInt willNotThreadWarnCount;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog MT VM [CoInterpreterMT VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog MT VM [CoInterpreterMT VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 int displayWidth;
 int displayDepth;
@@ -78682,6 +78683,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur64.sista/cointerp.c b/src/spur64.sista/cointerp.c
index 7f99041015..beefcd5f2a 100644
--- a/src/spur64.sista/cointerp.c
+++ b/src/spur64.sista/cointerp.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2677,8 +2677,9 @@ sqInt sendWheelEvents;
 sqInt suppressHeartbeatFlag;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 int displayWidth;
 int displayDepth;
@@ -79529,6 +79530,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur64.sista/cointerp.h b/src/spur64.sista/cointerp.h
index cab3ce9c1f..741574b361 100644
--- a/src/spur64.sista/cointerp.h
+++ b/src/spur64.sista/cointerp.h
@@ -1,5 +1,5 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
 
 
@@ -337,6 +337,7 @@ extern sqInt ultimateLiteralOf(sqInt aMethodOop);
 extern sqInt breakLookupClassTag;
 extern char * breakSelector;
 extern sqInt breakSelectorLength ;
+extern sqInt cannotDeferDisplayUpdates;
 extern sqInt checkedPluginName;
 extern sqInt checkForLeaks;
 extern sqInt debugCallbackInvokes;
diff --git a/src/spur64.sista/gcc3x-cointerp.c b/src/spur64.sista/gcc3x-cointerp.c
index 9e77bf4eb1..c74145b8fc 100644
--- a/src/spur64.sista/gcc3x-cointerp.c
+++ b/src/spur64.sista/gcc3x-cointerp.c
@@ -2,11 +2,11 @@
 
 
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2680,8 +2680,9 @@ sqInt sendWheelEvents;
 sqInt suppressHeartbeatFlag;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog[Spur] VM [CoInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 int displayWidth;
 int displayDepth;
@@ -79538,6 +79539,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur64.stack.lowcode/gcc3x-interp.c b/src/spur64.stack.lowcode/gcc3x-interp.c
index f9c9d37feb..4a3a8465b8 100644
--- a/src/spur64.stack.lowcode/gcc3x-interp.c
+++ b/src/spur64.stack.lowcode/gcc3x-interp.c
@@ -2,11 +2,11 @@
 
 
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2400,8 +2400,9 @@ sqInt sendWheelEvents;
 char * breakSelector;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt suppressHeartbeatFlag;
 int displayWidth;
 int displayDepth;
@@ -79521,6 +79522,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur64.stack.lowcode/interp.c b/src/spur64.stack.lowcode/interp.c
index 65f793093b..ee6a5e1a3e 100644
--- a/src/spur64.stack.lowcode/interp.c
+++ b/src/spur64.stack.lowcode/interp.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2397,8 +2397,9 @@ sqInt sendWheelEvents;
 char * breakSelector;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt suppressHeartbeatFlag;
 int displayWidth;
 int displayDepth;
@@ -79512,6 +79513,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur64.stack/gcc3x-interp.c b/src/spur64.stack/gcc3x-interp.c
index 249c287d7f..acdbfbc2b9 100644
--- a/src/spur64.stack/gcc3x-interp.c
+++ b/src/spur64.stack/gcc3x-interp.c
@@ -2,11 +2,11 @@
 
 
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2376,8 +2376,9 @@ sqInt sendWheelEvents;
 char * breakSelector;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt suppressHeartbeatFlag;
 int displayWidth;
 int displayDepth;
@@ -66537,6 +66538,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur64.stack/interp.c b/src/spur64.stack/interp.c
index 0ff9062148..5a1beaf500 100644
--- a/src/spur64.stack/interp.c
+++ b/src/spur64.stack/interp.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2373,8 +2373,9 @@ sqInt sendWheelEvents;
 char * breakSelector;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt suppressHeartbeatFlag;
 int displayWidth;
 int displayDepth;
@@ -66528,6 +66529,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/spur64.stack/validImage.c b/src/spur64.stack/validImage.c
index 3d83651c33..6720ddfe53 100644
--- a/src/spur64.stack/validImage.c
+++ b/src/spur64.stack/validImage.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	ImageLeakChecker VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	ImageLeakChecker VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "ImageLeakChecker VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "ImageLeakChecker VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -935,6 +935,7 @@ sqInt sendWheelEvents;
 sqInt breakLookupClassTag;
 char * breakSelector;
 sqInt breakSelectorLength = MinSmallInteger;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackPath;
@@ -948,7 +949,7 @@ sqInt extraVMMemory;
 sqInt ffiExceptionResponse;
 sqInt inIOProcessEvents;
 struct VirtualMachine* interpreterProxy;
-const char *interpreterVersion = "Open Smalltalk ImageChecker VM [ImageLeakChecker VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk ImageChecker VM [ImageLeakChecker VMMaker.oscog-mt.3184]";
 sqInt suppressHeartbeatFlag;
 int displayDepth;
 int displayHeight;
diff --git a/src/v3.cog/cointerp.c b/src/v3.cog/cointerp.c
index 3e309af2d7..25e3d5872a 100644
--- a/src/v3.cog/cointerp.c
+++ b/src/v3.cog/cointerp.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2242,8 +2242,9 @@ sqInt sendWheelEvents;
 sqInt suppressHeartbeatFlag;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog[SqueakV3] VM [CoInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog[SqueakV3] VM [CoInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 char expensiveAsserts = 0;
 int (*showSurfaceFn)(sqIntptr_t, int, int, int, int);
@@ -53974,6 +53975,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/v3.cog/cointerp.h b/src/v3.cog/cointerp.h
index f13cde0ec3..767566e119 100644
--- a/src/v3.cog/cointerp.h
+++ b/src/v3.cog/cointerp.h
@@ -1,5 +1,5 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
 
 
@@ -279,6 +279,7 @@ extern sqInt ultimateLiteralOf(sqInt aMethodOop);
 extern sqInt breakLookupClassTag;
 extern char * breakSelector;
 extern sqInt breakSelectorLength ;
+extern sqInt cannotDeferDisplayUpdates;
 extern sqInt checkedPluginName;
 extern sqInt checkForLeaks;
 extern sqInt debugCallbackInvokes;
diff --git a/src/v3.cog/gcc3x-cointerp.c b/src/v3.cog/gcc3x-cointerp.c
index ca4765616f..e5c370c955 100644
--- a/src/v3.cog/gcc3x-cointerp.c
+++ b/src/v3.cog/gcc3x-cointerp.c
@@ -2,11 +2,11 @@
 
 
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "CoInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "CoInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -2245,8 +2245,9 @@ sqInt sendWheelEvents;
 sqInt suppressHeartbeatFlag;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Cog[SqueakV3] VM [CoInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Cog[SqueakV3] VM [CoInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt minBackwardJumpCountForCompile = MinBackwardJumpCountForCompile /* 40 */;
 char expensiveAsserts = 0;
 int (*showSurfaceFn)(sqIntptr_t, int, int, int, int);
@@ -53983,6 +53984,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/v3.stack/gcc3x-interp.c b/src/v3.stack/gcc3x-interp.c
index 7fcc7eef5f..ee4cae08df 100644
--- a/src/v3.stack/gcc3x-interp.c
+++ b/src/v3.stack/gcc3x-interp.c
@@ -2,11 +2,11 @@
 
 
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -1976,8 +1976,9 @@ sqInt breakLookupClassTag;
 char * breakSelector;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt suppressHeartbeatFlag;
 char expensiveAsserts = 0;
 int (*showSurfaceFn)(sqIntptr_t, int, int, int, int);
@@ -44730,6 +44731,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {
diff --git a/src/v3.stack/interp.c b/src/v3.stack/interp.c
index 28bad73827..623aaf051d 100644
--- a/src/v3.stack/interp.c
+++ b/src/v3.stack/interp.c
@@ -1,9 +1,9 @@
 /* Automatically generated by
-	CCodeGeneratorGlobalStructure VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	CCodeGeneratorGlobalStructure VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
    from
-	StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6
+	StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7
  */
-static char __buildInfo[] = "StackInterpreter VMMaker.oscog-eem.3183 uuid: c5c103b4-2c5c-44e7-8e32-030e79600ca6 " __DATE__ ;
+static char __buildInfo[] = "StackInterpreter VMMaker.oscog-mt.3184 uuid: 57b61827-3f1a-ab45-966e-7c5caaef28d7 " __DATE__ ;
 char *__interpBuildInfo = __buildInfo;
 
 
@@ -1973,8 +1973,9 @@ sqInt breakLookupClassTag;
 char * breakSelector;
 sqInt debugCallbackInvokes;
 sqInt debugCallbackReturns;
+sqInt cannotDeferDisplayUpdates;
 sqInt checkedPluginName;
-const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-eem.3183]";
+const char *interpreterVersion = "Open Smalltalk Stack VM [StackInterpreterPrimitives VMMaker.oscog-mt.3184]";
 sqInt suppressHeartbeatFlag;
 char expensiveAsserts = 0;
 int (*showSurfaceFn)(sqIntptr_t, int, int, int, int);
@@ -44721,6 +44722,13 @@ primitiveDeferDisplayUpdates(void)
 {   DECL_MAYBE_SQ_GLOBAL_STRUCT
     sqInt flag;
 
+	if (cannotDeferDisplayUpdates) {
+		/* begin primitiveFail */
+		if (!GIV(primFailCode)) {
+			GIV(primFailCode) = 1;
+		}
+		return;
+	}
 	/* begin stackTop */
 	flag = longAt(GIV(stackPointer));
 	if (flag == GIV(trueObj)) {