A DESCRIPTION OF THE PROBLEM :
The method getBooleanProperty() in javafx.scene.PropertyHelper will always result in a NullPointerException on init. The exception is silently discarded. When using a debugger that is listening for all NPEs, this is quite annoying. This function and class isn't even necessary, it is just bad code.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Set a breakpoint in the catch block of the method, observe a NullPointerException when starting a JavaFX application unless property javafx.sg.warn is set.