When I lock screen my laptop with simple app running and unlock it I get
non-rendering app and a bunch of the following exceptions:

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$RunnableAdapter.call(Executors.java:441)
    at java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureTask.java:317)
    at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:150)
    at com.sun.prism.render.RenderJob.run(RenderJob.java:29)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at com.sun.javafx.tk.quantum.QuantumRenderer$ObservedRunnable.run(QuantumRenderer.java:70)
    at java.lang.Thread.run(Thread.java:662)

According to Kirill, this is a regression.