NullPointerException when using PopOver

Question

Original report by Sascha (Bitbucket: SaschaPro, GitHub: SaschaPro).

When I try to use the PopOver I always get the NPE shown below. There is also a thread in Google Groups: First attempt at PopOver fails

The code I use is this simple:

#!java

PopOver pop = new PopOver();
pop.show(refNode, 0, 0);

Here's the exception:

#!java

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
    at javafx.scene.Scene$ScenePulseListener.synchronizeSceneProperties(Scene.java:2323)
    at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2417)
    at com.sun.javafx.tk.Toolkit$3.run(Toolkit.java:322)
    at com.sun.javafx.tk.Toolkit$3.run(Toolkit.java:320)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:320)
    at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:349)
    at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:479)
    at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:460)
    at com.sun.javafx.tk.quantum.QuantumToolkit$13.run(QuantumToolkit.java:327)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.access$300(WinApplication.java:39)
    at com.sun.glass.ui.win.WinApplication$4$1.run(WinApplication.java:112)
    at java.lang.Thread.run(Thread.java:744)

该提问来源于开源项目：controlsfx/controlsfx

Answer 1

Original comment by Samir Hadzic (Bitbucket: shadzic, GitHub: shadzic).

Please open another issue, the stacktrace is different, it's a different problem.