To reproduce this issue just start attached app.
Then press <Ctrl>+<Alt>+<Delete> simultaneously ( it is usual action to call Task Manager, for example )

When you'll return to desktop this app will crash with such message:


java.lang.NullPointerException
at com.sun.prism.d3d.D3DSwapChain.present(D3DSwapChain.java:42)
at com.sun.javafx.tk.quantum.PaintRunnable.run(PaintRunnable.java:241)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureTask.java:351)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:178)
at com.sun.prism.render.RenderJob.run(RenderJob.java:29)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at com.sun.javafx.tk.quantum.QuantumRenderer$ObservedRunnable.run(QuantumRenderer.java:70)
at java.lang.Thread.run(Thread.java:722)


Very interesting, that if I remove button, this app works fine.