java.lang.NullPointerException
   at org.netbeans.modules.refactoring.spi.impl.RefactoringPanel.<init>(RefactoringPanel.java:164)
   at org.netbeans.modules.refactoring.spi.impl.RefactoringPanel.<init>(RefactoringPanel.java:156)
   at org.netbeans.modules.refactoring.spi.ui.UI.openRefactoringUI(UI.java:75)
   at org.netbeans.modules.groovy.refactoring.RefactoringTask$NodeToElementTask.run(RefactoringTask.java:281)
   at org.netbeans.modules.groovy.refactoring.RefactoringActionsProvider.doFindUsages(RefactoringActionsProvider.java:79)
   at org.netbeans.modules.refactoring.api.impl.ActionsImplementationFactory.doFindUsages(ActionsImplementationFactory.java:116)
   at org.netbeans.modules.refactoring.spi.impl.WhereUsedAction.performAction(WhereUsedAction.java:77)
   at org.netbeans.modules.refactoring.spi.impl.RefactoringGlobalAction.performAction(RefactoringGlobalAction.java:140)
   at org.openide.util.actions.NodeAction.performAction(NodeAction.java:295)
   at org.openide.util.actions.CallableSystemAction$1.run(CallableSystemAction.java:129)
   at org.openide.util.actions.ActionInvoker$1.run(ActionInvoker.java:95)
   at org.openide.util.actions.ActionInvoker.doPerformAction(ActionInvoker.java:116)
   at org.openide.util.actions.ActionInvoker.invokeAction(ActionInvoker.java:99)
   at org.openide.util.actions.CallableSystemAction.actionPerformed(CallableSystemAction.java:126)
   at org.openide.util.actions.NodeAction.actionPerformed(NodeAction.java:283)
   at org.openide.windows.TopComponent.processKeyBinding(TopComponent.java:1176)
   at javax.swing.JComponent.processKeyBindings(JComponent.java:2897)
   at javax.swing.JComponent.processKeyEvent(JComponent.java:2814)
   at java.awt.Component.processEvent(Component.java:6065)
   at java.awt.Container.processEvent(Container.java:2041)
   at java.awt.Component.dispatchEventImpl(Component.java:4651)
   at java.awt.Container.dispatchEventImpl(Container.java:2099)
   at java.awt.Component.dispatchEvent(Component.java:4481)
   at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1850)
   at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:712)
   at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:990)
   at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:855)
   at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:676)
   at java.awt.Component.dispatchEventImpl(Component.java:4523)
   at java.awt.Container.dispatchEventImpl(Container.java:2099)
   at java.awt.Window.dispatchEventImpl(Window.java:2478)
   at java.awt.Component.dispatchEvent(Component.java:4481)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:643)
   at java.awt.EventQueue.access$000(EventQueue.java:84)
   at java.awt.EventQueue$1.run(EventQueue.java:602)
   at java.awt.EventQueue$1.run(EventQueue.java:600)
   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:616)
   at java.awt.EventQueue$2.run(EventQueue.java:614)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:613)
   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)