Using an unknown property in selectors gives: Error: error evaluating rule type: error selecting entity: result is unknown

[jhrozek]

I managed to use a property that does not exist in a selector and I received an error:

Error: error evaluating rule type: error selecting entity: result is unknown

This should not have happened, we should have at the very least have thrown a better error message. Ideally, though, the profile shouldn't have errored but we should have proceeded with the evaluation - the properties are not guaranteed to be there.