D&D a node - choose Menubar > Edit > Delete - bug - following exception thrown

java.lang.AssertionError
at com.oracle.javafx.scenebuilder.kit.editor.job.PrunePropertiesJob.<init>(PrunePropertiesJob.java:58)
at com.oracle.javafx.scenebuilder.kit.editor.job.SetDocumentRootJob.execute(SetDocumentRootJob.java:84)
at com.oracle.javafx.scenebuilder.kit.editor.job.BatchJob.execute(BatchJob.java:117)
at com.oracle.javafx.scenebuilder.kit.editor.job.DeleteObjectJob.execute(DeleteObjectJob.java:118)
at com.oracle.javafx.scenebuilder.kit.editor.job.v2.CompositeJob.execute(CompositeJob.java:98)
at com.oracle.javafx.scenebuilder.kit.editor.job.DeleteSelectionJob.execute(DeleteSelectionJob.java:62)
at com.oracle.javafx.scenebuilder.kit.editor.JobManager.executeJob(JobManager.java:181)
at com.oracle.javafx.scenebuilder.kit.editor.JobManager.push(JobManager.java:70)
at com.oracle.javafx.scenebuilder.kit.editor.EditorController.performEditAction(EditorController.java:949)
at com.oracle.javafx.scenebuilder.app.DocumentWindowController.performDelete(DocumentWindowController.java:1494)
at com.oracle.javafx.scenebuilder.app.DocumentWindowController.performEditAction(DocumentWindowController.java:816)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController$DocumentEditActionController.perform(MenuBarController.java:1591)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController.handleOnActionMenu(MenuBarController.java:1114)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController.access$800(MenuBarController.java:90)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController$20.handle(MenuBarController.java:1107)
at com.oracle.javafx.scenebuilder.app.menubar.MenuBarController$20.handle(MenuBarController.java:1103)
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:49)
at javafx.event.Event.fireEvent(Event.java:204)
at javafx.scene.control.MenuItem.fire(MenuItem.java:462)
at com.sun.javafx.scene.control.GlobalMenuAdapter$5.handle(GlobalMenuAdapter.java:158)
at com.sun.javafx.scene.control.GlobalMenuAdapter$5.handle(GlobalMenuAdapter.java:156)
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:204)
at javafx.scene.control.MenuItem.fire(MenuItem.java:462)
at com.sun.javafx.tk.quantum.GlassSystemMenu$6.action(GlassSystemMenu.java:234)