java.lang.IllegalStateException: Should not acquire Children.MUTEX while holding ProjectManager.mutex()
        at org.openide.nodes.Children$ProjectManagerDeadlockDetector.execute(Children.java:1805)
        at org.openide.util.Mutex.doWrapperAccess(Mutex.java:1320)
        at org.openide.util.Mutex.readAccess(Mutex.java:275)
        at org.openide.explorer.view.TreeView$ExplorerTree$GuardedActions.<init>(TreeView.java:2086)
        at org.openide.explorer.view.TreeView$ExplorerTree.processFocusEvent(TreeView.java:1847)
        at java.awt.Component.processEvent(Component.java:5972)
        at java.awt.Container.processEvent(Container.java:2041)
        at java.awt.Component.dispatchEventImpl(Component.java:4583)
        at java.awt.Container.dispatchEventImpl(Container.java:2099)
        at java.awt.Component.dispatchEvent(Component.java:4413)
        at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1848)
        at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:889)
        at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:562)
        at java.awt.Component.dispatchEventImpl(Component.java:4455)
        at java.awt.Container.dispatchEventImpl(Container.java:2099)
        at java.awt.Component.dispatchEvent(Component.java:4413)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:104)
        at java.awt.SentEvent.dispatch(SentEvent.java:55)
        at java.awt.DefaultKeyboardFocusManager$DefaultKeyboardFocusManagerSentEvent.dispatch(DefaultKeyboardFocusManager.java:183)
        at java.awt.DefaultKeyboardFocusManager.sendMessage(DefaultKeyboardFocusManager.java:210)
        at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:627)
        at java.awt.Component.dispatchEventImpl(Component.java:4455)
        at java.awt.Container.dispatchEventImpl(Container.java:2099)
        at java.awt.Window.dispatchEventImpl(Window.java:2475)
        at java.awt.Component.dispatchEvent(Component.java:4413)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:104)
        at java.awt.SequencedEvent.dispatch(SequencedEvent.java:101)
        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:1051)
        at java.awt.Dialog$3.run(Dialog.java:1103)
        at java.security.AccessController.doPrivileged(AccessController.java:0)
        at java.awt.Dialog.show(Dialog.java:1101)
        at org.netbeans.core.windows.services.NbPresenter.superShow(NbPresenter.java:985)
        at org.netbeans.core.windows.services.NbPresenter.doShow(NbPresenter.java:1019)
        at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:1007)
        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:992)
        at java.awt.Component.show(Component.java:1516)
        at java.awt.Component.setVisible(Component.java:1468)
        at java.awt.Window.setVisible(Window.java:841)
        at java.awt.Dialog.setVisible(Dialog.java:991)
        at org.netbeans.core.windows.services.DialogDisplayerImpl$1AWTQuery.showDialog(DialogDisplayerImpl.java:232)
        at org.netbeans.core.windows.services.DialogDisplayerImpl.notify(DialogDisplayerImpl.java:248)
        at org.netbeans.core.windows.services.DialogDisplayerImpl.notify(DialogDisplayerImpl.java:146)
        at org.netbeans.modules.java.j2seproject.ui.customizer.J2SEProjectProperties.showModifiedMessage(J2SEProjectProperties.java:645)
        at org.netbeans.modules.java.j2seproject.ui.customizer.J2SEProjectProperties.checkModified(J2SEProjectProperties.java:443)
        at org.netbeans.modules.java.j2seproject.ui.customizer.CustomizerProviderImpl$OptionListener.actionPerformed(CustomizerProviderImpl.java:188)
        at org.netbeans.modules.project.uiapi.CustomizerDialog$OptionListener$1.run(CustomizerDialog.java:246)
        at org.openide.util.Mutex.writeAccess(Mutex.java:394)
        at org.netbeans.modules.project.uiapi.CustomizerDialog$OptionListener.actionPerformed(CustomizerDialog.java:244)
        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.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
        at java.awt.Component.processMouseEvent(Component.java:6216)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3265)
        at java.awt.Component.processEvent(Component.java:5981)
        at java.awt.Container.processEvent(Container.java:2041)
        at java.awt.Component.dispatchEventImpl(Component.java:4583)
        at java.awt.Container.dispatchEventImpl(Container.java:2099)
        at java.awt.Component.dispatchEvent(Component.java:4413)
        at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4556)
        at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:4220)
        at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4150)
        at java.awt.Container.dispatchEventImpl(Container.java:2085)
        at java.awt.Window.dispatchEventImpl(Window.java:2475)
        at java.awt.Component.dispatchEvent(Component.java:4413)
        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)