java.lang.NullPointerException
        at org.netbeans.modules.maven.nodes.SourcesNodeFactory$NList.node(SourcesNodeFactory.java:100)
        at org.netbeans.modules.maven.nodes.SourcesNodeFactory$NList.node(SourcesNodeFactory.java:80)
        at org.netbeans.spi.project.ui.support.NodeFactorySupport$DelegateChildren.createNodes(NodeFactorySupport.java:142)
        at org.netbeans.spi.project.ui.support.NodeFactorySupport$DelegateChildren.createNodes(NodeFactorySupport.java:120)
        at org.openide.nodes.Children$Keys$KE.nodes(Children.java:1602)
        at org.openide.nodes.ChildrenArray.nodesFor(ChildrenArray.java:168)
        at org.openide.nodes.EntrySupport$Default$Info.nodes(EntrySupport.java:925)
        at org.openide.nodes.EntrySupport$Default.updateAdd(EntrySupport.java:505)
        at org.openide.nodes.EntrySupport$Default.setEntries(EntrySupport.java:345)
        at org.openide.nodes.Children$Keys$2.run(Children.java:1496)
        at org.openide.util.Mutex$1Exec.run(Mutex.java:1239)
        at org.openide.nodes.Children$ProjectManagerDeadlockDetector.execute(Children.java:1802)
        at org.openide.util.Mutex.postRequest(Mutex.java:1245)
        at org.openide.util.Mutex.postRequest(Mutex.java:1209)
        at org.openide.util.Mutex.postWriteRequest(Mutex.java:582)
        at org.openide.nodes.Children$Keys.applyKeys(Children.java:1505)
        at org.openide.nodes.Children$Keys.setKeys(Children.java:1449)
        at org.netbeans.spi.project.ui.support.NodeFactorySupport$DelegateChildren.access$200(NodeFactorySupport.java:120)
        at org.netbeans.spi.project.ui.support.NodeFactorySupport$DelegateChildren$RunnableImpl.run(NodeFactorySupport.java:283)
        at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
        at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:104)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:178)
        at java.awt.Dialog$1.run(Dialog.java:1047)
        at java.awt.Dialog$3.run(Dialog.java:1099)
        at java.security.AccessController.doPrivileged(AccessController.java:0)
        at java.awt.Dialog.show(Dialog.java:1097)
        at org.netbeans.core.windows.services.NbPresenter.superShow(NbPresenter.java:988)
        at org.netbeans.core.windows.services.NbPresenter.doShow(NbPresenter.java:1022)
        at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:1010)
        at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:115)
        at org.openide.util.Mutex.doEventAccess(Mutex.java:1355)
        at org.openide.util.Mutex.readAccess(Mutex.java:268)
        at org.netbeans.core.windows.services.NbPresenter.show(NbPresenter.java:995)
        at java.awt.Component.show(Component.java:1447)
        at java.awt.Component.setVisible(Component.java:1400)
        at java.awt.Window.setVisible(Window.java:824)
        at java.awt.Dialog.setVisible(Dialog.java:987)
        at org.netbeans.modules.project.uiapi.DefaultProjectOperationsImplementation.showConfirmationDialog(DefaultProjectOperationsImplementation.java:688)
        at org.netbeans.modules.project.uiapi.DefaultProjectOperationsImplementation.access$300(DefaultProjectOperationsImplementation.java:98)
        at org.netbeans.modules.project.uiapi.DefaultProjectOperationsImplementation$GUIUserInputHandler.showConfirmationDialog(DefaultProjectOperationsImplementation.java:220)
        at org.netbeans.modules.project.uiapi.DefaultProjectOperationsImplementation.deleteProject(DefaultProjectOperationsImplementation.java:196)
        at org.netbeans.modules.project.uiapi.DefaultProjectOperationsImplementation.deleteProject(DefaultProjectOperationsImplementation.java:162)
        at org.netbeans.spi.project.ui.support.DefaultProjectOperations.performDefaultDeleteOperation(DefaultProjectOperations.java:85)
        at org.netbeans.modules.maven.ActionProviderImpl.invokeAction(ActionProviderImpl.java:153)
        at org.netbeans.modules.project.ui.actions.ProjectAction.actionPerformed(ProjectAction.java:129)
        at org.netbeans.modules.project.ui.actions.LookupSensitiveAction.actionPerformed(LookupSensitiveAction.java:161)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
        at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
        at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
        at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
        at javax.swing.AbstractButton.doClick(AbstractButton.java:357)
        at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1225)
        at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:1266)
        at java.awt.Component.processMouseEvent(Component.java:6134)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3265)
        at java.awt.Component.processEvent(Component.java:5899)
        at java.awt.Container.processEvent(Container.java:2023)
        at java.awt.Component.dispatchEventImpl(Component.java:4501)
        at java.awt.Container.dispatchEventImpl(Container.java:2081)
        at java.awt.Component.dispatchEvent(Component.java:4331)
        at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4301)
        at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:3965)
        at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:3895)
        at java.awt.Container.dispatchEventImpl(Container.java:2067)
        at java.awt.Window.dispatchEventImpl(Window.java:2458)
        at java.awt.Component.dispatchEvent(Component.java:4331)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:104)
        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)