To reproduce:
1) Start SB from IDE
2) Start Xcode and then Accessiblity Inspector
3) Window -> Accessiblity Verifier
4) Choose 'java' application
5) Click 'Verify'
=> SB throws a chain of NPE in the standard output


java.lang.Exception: SetThemeActionController.canPerform() did break for menu item RadioMenuItem[id=modenaThemeMenuItem, styleClass=[menu-item, radio-menu-item]]
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController.handleOnMenuValidation(MenuBarController.java:1055)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController.lambda$new$16(MenuBarController.java:1037)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController$$Lambda$71/1254176381.handle(Unknown Source)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.control.Menu.setShowing(Menu.java:176)
at javafx.scene.control.Menu.show(Menu.java:385)
at com.sun.javafx.scene.control.GlobalMenuAdapter.lambda$new$19(GlobalMenuAdapter.java:82)
at com.sun.javafx.scene.control.GlobalMenuAdapter$$Lambda$316/1502908896.invalidated(Unknown Source)
at com.sun.javafx.binding.ExpressionHelper$SingleInvalidation.fireValueChangedEvent(ExpressionHelper.java:137)
at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81)
at javafx.beans.property.ReadOnlyBooleanWrapper$ReadOnlyPropertyImpl.fireValueChangedEvent(ReadOnlyBooleanWrapper.java:178)
at javafx.beans.property.ReadOnlyBooleanWrapper$ReadOnlyPropertyImpl.access$100(ReadOnlyBooleanWrapper.java:148)
at javafx.beans.property.ReadOnlyBooleanWrapper.fireValueChangedEvent(ReadOnlyBooleanWrapper.java:144)
at javafx.beans.property.BooleanPropertyBase.markInvalid(BooleanPropertyBase.java:110)
at javafx.beans.property.BooleanPropertyBase.set(BooleanPropertyBase.java:143)
at javafx.scene.control.Menu.setShowing(Menu.java:187)
at javafx.scene.control.Menu.show(Menu.java:385)
at com.sun.javafx.tk.quantum.GlassMenuEventHandler.handleMenuOpening(GlassMenuEventHandler.java:41)
at com.sun.glass.ui.Menu.notifyMenuOpening(Menu.java:187)
Caused by: java.lang.NullPointerException
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController$SetThemeActionController.canPerform(MenuBarController.java:1779)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController.handleOnMenuValidation(MenuBarController.java:1048)
... 25 more