java.lang.IllegalStateException: Should not acquire Children.MUTEX while holding ProjectManager.mutex()
        at org.openide.nodes.Children$ProjectManagerDeadlockDetector.execute(Children.java:1807)
        at org.openide.util.Mutex.postRequest(Mutex.java:1245)
        at org.openide.util.Mutex.postRequest(Mutex.java:1209)
        at org.openide.util.Mutex.postWriteRequest(Mutex.java:582)
        at org.openide.nodes.Children$Keys.refreshKey(Children.java:1405)
        at org.netbeans.modules.apisupport.beanbrowser.PropSetKids.access$100(PropSetKids.java:65)
        at org.netbeans.modules.apisupport.beanbrowser.PropSetKids$1.propertyChange(PropSetKids.java:108)
        at org.openide.nodes.Node.firePropertyChange(Node.java:995)
        at org.openide.nodes.BeanNode$PropL.propertyChange(BeanNode.java:845)
        at org.openide.util.WeakListenerImpl$PropertyChange.propertyChange(WeakListenerImpl.java:187)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:339)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:276)
        at org.netbeans.modules.project.ant.ProjectLibraryProvider.configurationXmlChanged(ProjectLibraryProvider.java:204)
Caused: java.lang.reflect.InvocationTargetException
        at sun.reflect.GeneratedMethodAccessor67.invoke(GeneratedMethodAccessor67.java:0)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.openide.util.WeakListenerImpl$ProxyListener.invoke(WeakListenerImpl.java:450)
Caused: java.lang.reflect.UndeclaredThrowableException
        at $Proxy11.configurationXmlChanged(.java:0)
        at org.netbeans.spi.project.support.ant.AntProjectHelper$3.run(AntProjectHelper.java:493)
        at org.netbeans.spi.project.support.ant.AntProjectHelper$3.run(AntProjectHelper.java:488)
        at org.openide.util.Mutex.readAccess(Mutex.java:285)
        at org.netbeans.spi.project.support.ant.AntProjectHelper.fireChange(AntProjectHelper.java:488)
        at org.netbeans.spi.project.support.ant.AntProjectHelper.modifying(AntProjectHelper.java:516)
        at org.netbeans.spi.project.support.ant.AntProjectHelper.access$900(AntProjectHelper.java:101)
        at org.netbeans.spi.project.support.ant.AntProjectHelper$11.run(AntProjectHelper.java:930)
        at org.netbeans.spi.project.support.ant.AntProjectHelper$11.run(AntProjectHelper.java:923)
        at org.openide.util.Mutex.writeAccess(Mutex.java:394)
        at org.netbeans.spi.project.support.ant.AntProjectHelper.removeConfigurationFragment(AntProjectHelper.java:923)
        at org.netbeans.spi.project.support.ant.ExtensibleMetadataProviderImpl.removeConfigurationFragment(ExtensibleMetadataProviderImpl.java:98)
        at org.netbeans.modules.projectapi.AuxiliaryConfigImpl$3.run(AuxiliaryConfigImpl.java:271)
        at org.netbeans.modules.projectapi.AuxiliaryConfigImpl$3.run(AuxiliaryConfigImpl.java:266)
        at org.openide.util.Mutex.writeAccess(Mutex.java:394)
        at org.netbeans.modules.projectapi.AuxiliaryConfigImpl.removeConfigurationFragment(AuxiliaryConfigImpl.java:266)
        at org.netbeans.modules.project.ui.ProjectUtilities.openProjectFiles(ProjectUtilities.java:522)
        at org.netbeans.modules.project.ui.OpenProjectList$8.run(OpenProjectList.java:1115)
        at org.netbeans.modules.project.ui.OpenProjectList$8.run(OpenProjectList.java:1112)
        at org.openide.util.Mutex$1AWTWorker.run(Mutex.java:1370)
        at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:199)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
        at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:104)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:177)
        at java.awt.Dialog$1.run(Dialog.java:1045)
        at java.awt.Dialog$3.run(Dialog.java:1097)
        at java.security.AccessController.doPrivileged(AccessController.java:0)
        at java.awt.Dialog.show(Dialog.java:1095)
        at java.awt.Component.show(Component.java:1422)
        at java.awt.Component.setVisible(Component.java:1375)
        at java.awt.Window.setVisible(Window.java:806)
        at java.awt.Dialog.setVisible(Dialog.java:985)
        at org.netbeans.modules.project.ui.OpenProjectList.open(OpenProjectList.java:574)
        at org.netbeans.modules.project.ui.OpenProjectList$2.run(OpenProjectList.java:527)
        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:273)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)