java.lang.NullPointerException
   at java.awt.Component$NativeInLightFixer.removeReferences(Component.java:8863)
   at java.awt.Component$NativeInLightFixer.componentRemoved(Component.java:8839)
   at java.awt.Container.processContainerEvent(Container.java:2068)
   at java.awt.Container.processEvent(Container.java:2036)
   at java.awt.Component.dispatchEventImpl(Component.java:4653)
   at java.awt.Container.dispatchEventImpl(Container.java:2097)
   at java.awt.Component.dispatchEvent(Component.java:4481)
   at java.awt.Container.remove(Container.java:1160)
   at javax.swing.JLayeredPane.remove(JLayeredPane.java:227)
   at java.awt.Container.remove(Container.java:1196)
   at javax.swing.PopupFactory$ContainerPopup.hide(PopupFactory.java:483)
   at javax.swing.PopupFactory$MediumWeightPopup.hide(PopupFactory.java:862)
   at org.openide.explorer.view.ViewTooltips.ensureOldPopupsHidden(ViewTooltips.java:300)
   at org.openide.explorer.view.ViewTooltips.hide(ViewTooltips.java:288)
   at org.openide.explorer.view.ViewTooltips$Hider.change(ViewTooltips.java:670)
   at org.openide.explorer.view.ViewTooltips$Hider.propertyChange(ViewTooltips.java:676)
   at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:339)
   at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:276)
   at java.awt.KeyboardFocusManager.firePropertyChange(KeyboardFocusManager.java:1375)
   at java.awt.KeyboardFocusManager.setGlobalFocusOwner(KeyboardFocusManager.java:521)
   at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:537)
   at java.awt.Component.dispatchEventImpl(Component.java:4525)
   at java.awt.Container.dispatchEventImpl(Container.java:2097)
   at java.awt.Component.dispatchEvent(Component.java:4481)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:648)
   at java.awt.EventQueue.access$000(EventQueue.java:84)
   at java.awt.EventQueue$1.run(EventQueue.java:607)
   at java.awt.EventQueue$1.run(EventQueue.java:605)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
   at java.awt.EventQueue$2.run(EventQueue.java:621)
   at java.awt.EventQueue$2.run(EventQueue.java:619)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:618)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:158)
   at java.awt.SentEvent.dispatch(SentEvent.java:55)
   at java.awt.DefaultKeyboardFocusManager$DefaultKeyboardFocusManagerSentEvent.dispatch(DefaultKeyboardFocusManager.java:183)
   at java.awt.DefaultKeyboardFocusManager.sendMessage(DefaultKeyboardFocusManager.java:210)
   at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:635)
   at java.awt.Component.dispatchEventImpl(Component.java:4525)
   at java.awt.Container.dispatchEventImpl(Container.java:2097)
   at java.awt.Window.dispatchEventImpl(Window.java:2482)
   at java.awt.Component.dispatchEvent(Component.java:4481)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:648)
   at java.awt.EventQueue.access$000(EventQueue.java:84)
   at java.awt.EventQueue$1.run(EventQueue.java:607)
   at java.awt.EventQueue$1.run(EventQueue.java:605)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
   at java.awt.EventQueue$2.run(EventQueue.java:621)
   at java.awt.EventQueue$2.run(EventQueue.java:619)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:618)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:158)
   at java.awt.SequencedEvent.dispatch(SequencedEvent.java:101)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:646)
   at java.awt.EventQueue.access$000(EventQueue.java:84)
   at java.awt.EventQueue$1.run(EventQueue.java:607)
   at java.awt.EventQueue$1.run(EventQueue.java:605)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
   at java.awt.EventQueue$2.run(EventQueue.java:621)
   at java.awt.EventQueue$2.run(EventQueue.java:619)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:618)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:158)
   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)