Resizing an app's window, then re-entering with the mouse causes the attached exception.

According to this forum post, the issue existed in jdk7u6 preview 24 as well: https://forums.oracle.com/forums/thread.jspa?threadID=2427349

The app continues to run just fine. I have not noticed any performance problems, though the poster in the thread above seems to have performance problems who might be caused by this bug.

It seems that _any_ JavaFX app suffers this bug.