Steps to reproduce:
 - open ensemble or other sample app
 - press Alt+Tab

Exception will be thrown:

java.lang.NullPointerException
at com.sun.javafx.scene.KeyboardShortcutsHandler.processMnemonicsKeyDisplay(KeyboardShortcutsHandler.java:248)
at com.sun.javafx.scene.KeyboardShortcutsHandler.setMnemonicsDisplayEnabled(KeyboardShortcutsHandler.java:273)
at com.sun.javafx.scene.KeyboardShortcutsHandler.dispatchBubblingEvent(KeyboardShortcutsHandler.java:109)
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.EventUtil.fireEventImpl(EventUtil.java:47)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:33)
at javafx.event.Event.fireEvent(Event.java:171)
at javafx.scene.Scene$KeyHandler.process(Scene.java:2821)
at javafx.scene.Scene$KeyHandler.access$1500(Scene.java:2751)
at javafx.scene.Scene.impl_processKeyEvent(Scene.java:1353)
at javafx.scene.Scene$ScenePeerListener.keyEvent(Scene.java:1784)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleKeyEvent(GlassViewEventHandler.java:105)
at com.sun.glass.ui.View.handleKeyEvent(View.java:248)
at com.sun.glass.ui.View.notifyKey(View.java:534)
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$2$1.run(WinApplication.java:62)
at java.lang.Thread.run(Thread.java:722)
java.lang.NullPointerException
at com.sun.javafx.scene.KeyboardShortcutsHandler.processMnemonicsKeyDisplay(KeyboardShortcutsHandler.java:248)
at com.sun.javafx.scene.KeyboardShortcutsHandler.setMnemonicsDisplayEnabled(KeyboardShortcutsHandler.java:273)
at com.sun.javafx.scene.KeyboardShortcutsHandler.dispatchBubblingEvent(KeyboardShortcutsHandler.java:114)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:38)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:37)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:35)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:92)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:47)
width = 527.0
height = 512.0
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:33)
at javafx.event.Event.fireEvent(Event.java:171)
at javafx.scene.Scene$KeyHandler.process(Scene.java:2821)
at javafx.scene.Scene$KeyHandler.access$1500(Scene.java:2751)
at javafx.scene.Scene.impl_processKeyEvent(Scene.java:1353)
at javafx.scene.Scene$ScenePeerListener.keyEvent(Scene.java:1784)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleKeyEvent(GlassViewEventHandler.java:105)
at com.sun.glass.ui.View.handleKeyEvent(View.java:248)
at com.sun.glass.ui.View.notifyKey(View.java:534)
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$2$1.run(WinApplication.java:62)
at java.lang.Thread.run(Thread.java:722)