java.lang.NoClassDefFoundError: org/openide/util/Enumerations$1RDupls
   at org.openide.util.Enumerations.removeDuplicates(Enumerations.java:143)
   at org.openide.actions.FileSystemAction.createMenu(FileSystemAction.java:177)
   at org.openide.actions.FileSystemAction.createMenu(FileSystemAction.java:159)
   at org.openide.actions.FileSystemAction$Menu.<init>(FileSystemAction.java:269)
   at org.openide.actions.FileSystemAction$DelegateAction.getPopupPresenter(FileSystemAction.java:358)
   at org.openide.util.Utilities.actionsToPopup(Utilities.java:2772)
   at org.openide.util.Utilities.actionsToPopup(Utilities.java:2858)
   at org.openide.explorer.view.TreeView.createPopup(TreeView.java:1070)
   at org.openide.explorer.view.TreeView$PopupAdapter.showPopup(TreeView.java:1558)
   at org.openide.awt.MouseUtils$PopupMouseAdapter.maybePopup(MouseUtils.java:189)
   at org.openide.awt.MouseUtils$PopupMouseAdapter.mousePressed(MouseUtils.java:180)
   at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:280)
   at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:279)
   at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:279)
   at java.awt.Component.processMouseEvent(Component.java:6502)
   at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
   at java.awt.Component.processEvent(Component.java:6270)
   at java.awt.Container.processEvent(Container.java:2229)
   at java.awt.Component.dispatchEventImpl(Component.java:4861)
   at java.awt.Container.dispatchEventImpl(Container.java:2287)
   at java.awt.Component.dispatchEvent(Component.java:4687)
   at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4832)
   at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:4489)
   at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4422)
   at java.awt.Container.dispatchEventImpl(Container.java:2273)
   at java.awt.Window.dispatchEventImpl(Window.java:2719)
   at java.awt.Component.dispatchEvent(Component.java:4687)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:703)
   at java.awt.EventQueue.access$000(EventQueue.java:102)
   at java.awt.EventQueue$3.run(EventQueue.java:662)
   at java.awt.EventQueue$3.run(EventQueue.java:660)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
   at java.awt.EventQueue$4.run(EventQueue.java:676)
   at java.awt.EventQueue$4.run(EventQueue.java:674)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:673)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:162)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)