java.lang.NullPointerException
   at java.awt.Dialog.conditionalShow(Dialog.java:936)
   at java.awt.Dialog.show(Dialog.java:1030)
   at org.netbeans.core.windows.services.NbPresenter.superShow(NbPresenter.java:1052)
   at org.netbeans.core.windows.services.NbPresenter.doShow(NbPresenter.java:1086)
   at org.netbeans.core.windows.services.NbPresenter.show(NbPresenter.java:1062)
   at java.awt.Component.show(Component.java:1651)
   at java.awt.Component.setVisible(Component.java:1603)
   at java.awt.Window.setVisible(Window.java:1014)
   at java.awt.Dialog.setVisible(Dialog.java:1003)
   at org.netbeans.core.windows.services.DialogDisplayerImpl$1AWTQuery.showDialog(DialogDisplayerImpl.java:249)
   at org.netbeans.core.windows.services.DialogDisplayerImpl.notify(DialogDisplayerImpl.java:265)
   at org.netbeans.core.windows.services.DialogDisplayerImpl.notify(DialogDisplayerImpl.java:158)
   at org.netbeans.modules.maven.ActionProviderImpl$ShowProblemsAction.actionPerformed(ActionProviderImpl.java:536)
   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:2719)
   at java.awt.Component.dispatchEvent(Component.java:4687)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:713)
   at java.awt.EventQueue.access$000(EventQueue.java:104)
   at java.awt.EventQueue$3.run(EventQueue.java:672)
   at java.awt.EventQueue$3.run(EventQueue.java:670)
   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:686)
   at java.awt.EventQueue$4.run(EventQueue.java:684)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:683)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:162)
   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)