java.lang.ClassCastException: org.openide.text.UndoRedoManager cannot be cast to org.netbeans.modules.xml.xam.ui.undo.QuietUndoManager
   at org.netbeans.modules.xml.schema.SchemaEditorSupport.getUndoManager(SchemaEditorSupport.java:264)
   at org.netbeans.modules.xml.schema.SchemaEditorSupport$5.taskFinished(SchemaEditorSupport.java:632)
   at org.openide.util.Task.addTaskListener(Task.java:266)
   at org.netbeans.modules.xml.schema.SchemaEditorSupport.prepareDocument(SchemaEditorSupport.java:630)
   at org.openide.text.CloneableEditorSupport.createCloneableTopComponent(CloneableEditorSupport.java:1364)
   at org.openide.windows.CloneableOpenSupport.openCloneableTopComponent(CloneableOpenSupport.java:200)
   at org.openide.windows.CloneableOpenSupport$1.run(CloneableOpenSupport.java:101)
   at org.openide.util.Mutex.doEvent(Mutex.java:1341)
   at org.openide.util.Mutex.writeAccess(Mutex.java:455)
   at org.openide.windows.CloneableOpenSupport.open(CloneableOpenSupport.java:98)
   at org.openide.text.CloneableEditorSupport.open(CloneableEditorSupport.java:512)
   at org.netbeans.modules.versioning.system.cvss.ui.syncview.OpenInEditorAction.openByCookie(OpenInEditorAction.java:113)
   at org.netbeans.modules.versioning.system.cvss.ui.syncview.OpenInEditorAction.openDataObjectByCookie(OpenInEditorAction.java:105)
   at org.netbeans.modules.versioning.system.cvss.ui.syncview.OpenInEditorAction.actionPerformed(OpenInEditorAction.java:89)
   at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
   at javax.swing.AbstractButton$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:6504)
   at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
   at java.awt.Component.processEvent(Component.java:6269)
   at java.awt.Container.processEvent(Container.java:2229)
   at java.awt.Component.dispatchEventImpl(Component.java:4860)
   at java.awt.Container.dispatchEventImpl(Container.java:2287)
   at java.awt.Component.dispatchEvent(Component.java:4686)
   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:4686)
   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:162)
   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)