Posted by Mr.Marbles on Aug 28, 2015; 7:27pm
URL: https://forum.jogamp.org/JOGL-2-support-for-Ardor3D-JMonkeyEngine-3-jzy3d-and-NiftyGUI-tp1706747p4035170.html

I've gotten a little further. If Application.startCanvas() is not explicitly called, or it's called with a false value, then the JFrame will always show and we can see the rendered scene for about 5sec. At that point the exception will be thrown because of a lock timeout in RecursiveLockImpl01Unfairish. From the stacktrace is seems the JOGL system is never notified that the canvas is being repainted from EDT and so it times out.