java.lang.NullPointerException at org.netbeans.modules.refactoring.java.plugins.ExtractSuperclassRefactoringPlugin.findUsedGenericTypes(ExtractSuperclassRefactoringPlugin.java:285) at org.netbeans.modules.refactoring.java.plugins.ExtractSuperclassRefactoringPlugin.access$100(ExtractSuperclassRefactoringPlugin.java:85) at org.netbeans.modules.refactoring.java.plugins.ExtractSuperclassRefactoringPlugin$CreateSuperclassElement.run(ExtractSuperclassRefactoringPlugin.java:437) at org.netbeans.modules.refactoring.java.plugins.ExtractSuperclassRefactoringPlugin$CreateSuperclassElement.run(ExtractSuperclassRefactoringPlugin.java:335) at org.netbeans.api.java.source.JavaSource$1.run(JavaSource.java:670) at org.netbeans.api.java.source.JavaSource$1.run(JavaSource.java:660) at org.netbeans.api.java.source.JavaSource$MultiTask.run(JavaSource.java:487) at org.netbeans.modules.parsing.impl.TaskProcessor.callUserTask(TaskProcessor.java:583) at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:150) at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:134) at org.netbeans.modules.parsing.impl.TaskProcessor$2.call(TaskProcessor.java:200) at org.netbeans.modules.parsing.impl.TaskProcessor$2.call(TaskProcessor.java:197) at org.netbeans.modules.masterfs.filebasedfs.utils.FileChangedManager.priorityIO(FileChangedManager.java:168) at org.netbeans.modules.masterfs.providers.ProvidedExtensions.priorityIO(ProvidedExtensions.java:360) at org.netbeans.modules.parsing.impl.Utilities.runPriorityIO(Utilities.java:72) at org.netbeans.modules.parsing.impl.TaskProcessor.runUserTask(TaskProcessor.java:197) at org.netbeans.modules.parsing.api.ParserManager.parse(ParserManager.java:102) at org.netbeans.api.java.source.JavaSource.runUserActionTaskImpl(JavaSource.java:437) at org.netbeans.api.java.source.JavaSource.runUserActionTask(JavaSource.java:408) at org.netbeans.api.java.source.JavaSource.runModificationTask(JavaSource.java:681) at org.netbeans.modules.refactoring.java.plugins.ExtractSuperclassRefactoringPlugin$CreateSuperclassElement.performChange(ExtractSuperclassRefactoringPlugin.java:372) at org.netbeans.modules.refactoring.api.RefactoringSession.doRefactoring(RefactoringSession.java:137) at org.netbeans.modules.refactoring.spi.impl.ParametersPanel$10.run(ParametersPanel.java:498) at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1452) at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2032) Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.NullPointerException at org.openide.util.RequestProcessor.post(RequestProcessor.java:424) at org.netbeans.modules.refactoring.spi.impl.ParametersPanel.refactor(ParametersPanel.java:461) at org.netbeans.modules.refactoring.spi.impl.ParametersPanel.refactor(ParametersPanel.java:516) at org.netbeans.modules.refactoring.spi.impl.ParametersPanel.access$200(ParametersPanel.java:86) at org.netbeans.modules.refactoring.spi.impl.ParametersPanel$3.actionPerformed(ParametersPanel.java:245) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018) at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341) at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402) at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259) at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252) at java.awt.Component.processMouseEvent(Component.java:6505) 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:4492) at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4422) at java.awt.Container.dispatchEventImpl(Container.java:2273) at java.awt.Window.dispatchEventImpl(Window.java:2713) at java.awt.Component.dispatchEvent(Component.java:4687) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:707) at java.awt.EventQueue.access$000(EventQueue.java:101) at java.awt.EventQueue$3.run(EventQueue.java:666) at java.awt.EventQueue$3.run(EventQueue.java:664) 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:680) at java.awt.EventQueue$4.run(EventQueue.java:678) at java.security.AccessController.doPrivileged(AccessController.java:0) at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76) at java.awt.EventQueue.dispatchEvent(EventQueue.java:677) at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:158) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:121) at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:182) at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:221) at java.security.AccessController.doPrivileged(AccessController.java:0) at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:219) at java.awt.Dialog.show(Dialog.java:1072) at org.netbeans.core.windows.services.NbPresenter.superShow(NbPresenter.java:1051) at org.netbeans.core.windows.services.NbPresenter.doShow(NbPresenter.java:1085) at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:1073) at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:125) at org.openide.util.Mutex.doEventAccess(Mutex.java:1361) at org.openide.util.Mutex.readAccess(Mutex.java:271) at org.netbeans.core.windows.services.NbPresenter.show(NbPresenter.java:1058) at java.awt.Component.show(Component.java:1651) at java.awt.Component.setVisible(Component.java:1603) at java.awt.Window.setVisible(Window.java:1013) at java.awt.Dialog.setVisible(Dialog.java:1003) at org.netbeans.modules.refactoring.spi.impl.ParametersPanel.showDialog(ParametersPanel.java:707) at org.netbeans.modules.refactoring.spi.impl.RefactoringPanel.refresh(RefactoringPanel.java:672) at org.netbeans.modules.refactoring.spi.impl.RefactoringPanel.(RefactoringPanel.java:155) at org.netbeans.modules.refactoring.spi.ui.UI.openRefactoringUI(UI.java:86) at org.netbeans.modules.refactoring.java.ui.ContextAnalyzer$4.show(ContextAnalyzer.java:551) at org.netbeans.modules.refactoring.java.ui.ContextAnalyzer$TextComponentTask.run(ContextAnalyzer.java:380) at org.netbeans.api.java.source.ui.ScanDialog.runWhenScanFinished(ScanDialog.java:153) at org.netbeans.modules.refactoring.java.ui.JavaRefactoringActionsProvider.doExtractSuperclass(JavaRefactoringActionsProvider.java:75) at org.netbeans.modules.refactoring.java.ui.JavaActionsImplementationFactory.doExtractSuperclass(JavaActionsImplementationFactory.java:134) at org.netbeans.modules.refactoring.java.ui.ExtractSuperclassAction.performAction(ExtractSuperclassAction.java:68) at org.netbeans.modules.refactoring.java.ui.JavaRefactoringGlobalAction$ContextAction.actionPerformed(JavaRefactoringGlobalAction.java:196) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018) at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341) at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402) at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259) at javax.swing.AbstractButton.doClick(AbstractButton.java:376) at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:833) at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:877) at java.awt.Component.processMouseEvent(Component.java:6505) 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:4492) at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4422) at java.awt.Container.dispatchEventImpl(Container.java:2273) at java.awt.Window.dispatchEventImpl(Window.java:2713) at java.awt.Component.dispatchEvent(Component.java:4687) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:707) at java.awt.EventQueue.access$000(EventQueue.java:101) at java.awt.EventQueue$3.run(EventQueue.java:666) at java.awt.EventQueue$3.run(EventQueue.java:664) 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:680) at java.awt.EventQueue$4.run(EventQueue.java:678) at java.security.AccessController.doPrivileged(AccessController.java:0) at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76) at java.awt.EventQueue.dispatchEvent(EventQueue.java:677) at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:158) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105) at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)