java.lang.NullPointerException at org.openide.util.lookup.ProxyLookup$R.lookupChange(ProxyLookup.java:461) at org.openide.util.lookup.ProxyLookup.setData(ProxyLookup.java:314) at org.openide.util.lookup.ProxyLookup.setLookups(ProxyLookup.java:153) at org.openide.util.lookup.ProxyLookup.setLookups(ProxyLookup.java:126) at org.netbeans.core.multiview.MultiViewTopComponentLookup$MyProxyLookup.setElementLookup(MultiViewTopComponentLookup.java:208) at org.netbeans.core.multiview.MultiViewTopComponentLookup.setElementLookup(MultiViewTopComponentLookup.java:71) at org.netbeans.core.multiview.MultiViewPeer.assignLookup(MultiViewPeer.java:242) at org.netbeans.core.multiview.MultiViewPeer.assignLookup(MultiViewPeer.java:254) at org.netbeans.core.multiview.MultiViewCloneableTopComponent.getLookup(MultiViewCloneableTopComponent.java:118) at org.netbeans.modules.localhistory.LocalHistory$OpenedFilesListener.getFiles(LocalHistory.java:538) at org.netbeans.modules.localhistory.LocalHistory$OpenedFilesListener.access$200(LocalHistory.java:454) at org.netbeans.modules.localhistory.LocalHistory$OpenedFilesListener$1.run(LocalHistory.java:465) at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1432) at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2042) Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.NullPointerException at org.openide.util.RequestProcessor.post(RequestProcessor.java:424) at org.netbeans.modules.localhistory.LocalHistory$OpenedFilesListener.propertyChange(LocalHistory.java:458) at java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:335) at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:327) at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:263) at org.netbeans.core.windows.RegistryImpl.doFirePropertyChange(RegistryImpl.java:329) at org.netbeans.core.windows.RegistryImpl.topComponentOpened(RegistryImpl.java:187) at org.netbeans.core.windows.WindowManagerImpl.notifyRegistryTopComponentOpened(WindowManagerImpl.java:1178) at org.netbeans.core.windows.WindowManagerImpl.notifyTopComponentOpened(WindowManagerImpl.java:1146) at org.netbeans.core.windows.Central.addModeOpenedTopComponent(Central.java:798) at org.netbeans.core.windows.ModeImpl.addOpenedTopComponent(ModeImpl.java:354) at org.netbeans.core.windows.WindowManagerImpl.topComponentOpenAtTabPosition(WindowManagerImpl.java:1256) at org.netbeans.core.windows.WindowManagerImpl.topComponentOpen(WindowManagerImpl.java:1221) at org.openide.windows.TopComponent.open(TopComponent.java:497) at org.openide.windows.TopComponent.open(TopComponent.java:477) at org.openide.windows.CloneableOpenSupport.openCloneableTopComponent(CloneableOpenSupport.java:202) at org.openide.windows.CloneableOpenSupport$1.run(CloneableOpenSupport.java:101) at org.openide.util.Mutex.doEvent(Mutex.java:1343) at org.openide.util.Mutex.writeAccess(Mutex.java:457) at org.openide.windows.CloneableOpenSupport.open(CloneableOpenSupport.java:98) at org.openide.text.CloneableEditorSupport.open(CloneableEditorSupport.java:510) at org.netbeans.modules.properties.PropertiesEditorSupport.open(PropertiesEditorSupport.java:420) at org.openide.windows.CloneableOpenSupport.edit(CloneableOpenSupport.java:121) at org.openide.awt.ActionDefaultPerfomer.actionPerformed(ActionDefaultPerfomer.java:76) at org.openide.awt.ContextAction$Performer.actionPerformed(ContextAction.java:226) at org.openide.awt.ContextManager.actionPerformed(ContextManager.java:257) at org.openide.awt.ContextAction.actionPerformed(ContextAction.java:109) at org.openide.util.actions.ActionInvoker$1.run(ActionInvoker.java:93) at org.openide.util.actions.ActionInvoker.doPerformAction(ActionInvoker.java:116) at org.openide.util.actions.ActionInvoker.invokeAction(ActionInvoker.java:99) at org.openide.awt.GeneralAction$BaseDelAction.actionPerformed(GeneralAction.java:234) at org.openide.explorer.view.TreeView$PopupSupport.mouseClicked(TreeView.java:1625) at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:270) at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:269) at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:269) at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:269) at java.awt.Component.processMouseEvent(Component.java:6508) 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:4501) 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:735) at java.awt.EventQueue.access$200(EventQueue.java:103) at java.awt.EventQueue$3.run(EventQueue.java:694) at java.awt.EventQueue$3.run(EventQueue.java:692) 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:708) at java.awt.EventQueue$4.run(EventQueue.java:706) at java.security.AccessController.doPrivileged(AccessController.java:0) at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76) at java.awt.EventQueue.dispatchEvent(EventQueue.java:705) at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138) at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)