java.lang.NullPointerException
        at javax.swing.JComponent._paintImmediately(JComponent.java:5122)
        at javax.swing.JComponent.paintImmediately(JComponent.java:4917)
        at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:743)
        at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:699)
        at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:679)
        at javax.swing.RepaintManager.access$700(RepaintManager.java:58)
        at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1553)
        at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:227)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:613)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:276)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:201)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:195)
        at java.awt.Dialog$1.run(Dialog.java:1066)
        at java.awt.Dialog$3.run(Dialog.java:1120)
        at java.security.AccessController.doPrivileged(AccessController.java:0)
        at java.awt.Dialog.show(Dialog.java:1118)
        at org.netbeans.core.windows.services.NbPresenter.superShow(NbPresenter.java:834)
        at org.netbeans.core.windows.services.NbPresenter.doShow(NbPresenter.java:868)
        at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:856)
        at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:104)
        at org.openide.util.Mutex$1AWTWorker.run(Mutex.java:1238)
        at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:217)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:613)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:276)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:201)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:191)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:186)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:178)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:139)