java.lang.IllegalStateException: Known problem in JDK occurred. If you are interested, vote and report at:
http://bugs.sun.com/view_bug.do?bug_id=6424157, http://bugs.sun.com/view_bug.do?bug_id=6553239 
Also see related discussion at http://www.netbeans.org/issues/show_bug.cgi?id=90590
        at org.netbeans.core.windows.WindowManagerImpl.warnIfNotInEDT(WindowManagerImpl.java:1558)
        at org.netbeans.core.windows.WindowManagerImpl.getMainWindow(WindowManagerImpl.java:157)
        at org.netbeans.core.TimableEventQueue.tick(TimableEventQueue.java:178)
        at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:130)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)