Run the KeyEvent demo in Ensemble :
  Ensemble -> Scenegraph -> Events -> KeyEvents

type any key in the textbox :

java.lang.NullPointerException
        at javafx.scene.control.ListCell$5.invalidated(ListCell.java:131)
        at javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:56)
        at javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:107)
        at javafx.scene.control.ListCell.setListView(ListCell.java:89)
        at javafx.scene.control.ListCell.impl_updateListView(ListCell.java:252)
        at com.sun.javafx.scene.control.skin.ListViewSkin.updateCellCount(ListViewSkin.java:149)
        at com.sun.javafx.scene.control.skin.ListViewSkin.access$600(ListViewSkin.java:26)
        at com.sun.javafx.scene.control.skin.ListViewSkin$12.onChanged(ListViewSkin.java:119)
        at com.sun.javafx.collections.ObservableListWrapper.callObservers(ObservableListWrapper.java:62)
        at com.sun.javafx.collections.ObservableListWrapper.add(ObservableListWrapper.java:81)
        at com.sun.javafx.collections.ObservableListWrapper.add(ObservableListWrapper.java:74)
        at com.javafx.experiments.ensemble2.samples.scenegraph.events.KeyEventsSample$2.handle(KeyEventsSample.java:75)
        at com.javafx.experiments.ensemble2.samples.scenegraph.events.KeyEventsSample$2.handle(KeyEventsSample.java:73)
        at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:59)
        at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:161)
        at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:114)
        at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:38)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:37)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
        at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:44)
        at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:33)
        at javafx.event.Event.fireEvent(Event.java:156)
        at javafx.scene.Scene$KeyHandler.process(Scene.java:2342)
        at javafx.scene.Scene$KeyHandler.access$1300(Scene.java:2272)
        at javafx.scene.Scene.impl_processKeyEvent(Scene.java:1233)
        at javafx.scene.Scene$ScenePeerListener.keyEvent(Scene.java:1639)
        at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleKeyEvent(GlassViewEventHandler.java:93)
        at com.sun.glass.ui.View.handleKeyEvent(View.java:236)
        at com.sun.glass.ui.View.notifyKey(View.java:514)
        at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
        at com.sun.glass.ui.win.WinApplication.access$100(WinApplication.java:29)
        at com.sun.glass.ui.win.WinApplication$1$1.run(WinApplication.java:49)
        at java.lang.Thread.run(Thread.java:619)