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:241) at org.netbeans.core.multiview.MultiViewPeer.assignLookup(MultiViewPeer.java:253) 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.insertModeOpenedTopComponent(Central.java:841) at org.netbeans.core.windows.ModeImpl.addOpenedTopComponent(ModeImpl.java:362) at org.netbeans.core.windows.LazyLoader.loadNow(LazyLoader.java:162) at org.netbeans.core.windows.LazyLoader.access$400(LazyLoader.java:62) at org.netbeans.core.windows.LazyLoader$2.run(LazyLoader.java:129) at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:721) at java.awt.EventQueue.access$200(EventQueue.java:103) at java.awt.EventQueue$3.run(EventQueue.java:682) at java.awt.EventQueue$3.run(EventQueue.java:680) at java.security.AccessController.doPrivileged(AccessController.java:0) at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76) at java.awt.EventQueue.dispatchEvent(EventQueue.java:691) at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159) 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)