java.lang.NullPointerException
   at javax.swing.plaf.basic.BasicTreeUI$Actions.traverse(BasicTreeUI.java:4393)
   at javax.swing.plaf.basic.BasicTreeUI$Actions.actionPerformed(BasicTreeUI.java:4049)
   at javax.swing.SwingUtilities.notifyAction(SwingUtilities.java:1663)
   at javax.swing.JComponent.processKeyBinding(JComponent.java:2882)
   at javax.swing.JComponent.processKeyBindings(JComponent.java:2929)
   at javax.swing.JComponent.processKeyEvent(JComponent.java:2845)
   at org.openide.explorer.view.TreeView$ExplorerTree.processKeyEvent(TreeView.java:1911)
   at java.awt.Component.processEvent(Component.java:6302)
   at java.awt.Container.processEvent(Container.java:2234)
   at java.awt.Component.dispatchEventImpl(Component.java:4881)
   at java.awt.Container.dispatchEventImpl(Container.java:2292)
   at java.awt.Component.dispatchEvent(Component.java:4703)
   at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1954)
   at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:806)
   at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:1074)
   at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:945)
   at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:771)
   at java.awt.Component.dispatchEventImpl(Component.java:4752)
   at java.awt.Container.dispatchEventImpl(Container.java:2292)
   at java.awt.Window.dispatchEventImpl(Window.java:2750)
   at java.awt.Component.dispatchEvent(Component.java:4703)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
   at java.awt.EventQueue.access$500(EventQueue.java:97)
   at java.awt.EventQueue$3.run(EventQueue.java:709)
   at java.awt.EventQueue$3.run(EventQueue.java:703)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:86)
   at java.awt.EventQueue$4.run(EventQueue.java:731)
   at java.awt.EventQueue$4.run(EventQueue.java:729)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)