java.lang.UnsupportedOperationException: prepareForUndoRedo access not supported.
   at org.netbeans.modules.xml.xam.dom.ReadOnlyAccess.prepareForUndoRedo(ReadOnlyAccess.java:441)
   at org.netbeans.modules.xml.xam.AbstractModel$ModelUndoableEdit.justUndo(AbstractModel.java:682)
   at org.netbeans.modules.xml.xam.AbstractModel$ModelUndoableEditSupport.abortUpdate(AbstractModel.java:177)
   at org.netbeans.modules.xml.xam.AbstractModel.rollbackTransaction(AbstractModel.java:440)
   at org.netbeans.modules.maven.customizer.CustomizerProviderImpl$OptionListener.windowClosed(CustomizerProviderImpl.java:347)
   at java.awt.AWTEventMulticaster.windowClosed(AWTEventMulticaster.java:343)
   at java.awt.AWTEventMulticaster.windowClosed(AWTEventMulticaster.java:342)
   at java.awt.AWTEventMulticaster.windowClosed(AWTEventMulticaster.java:342)
   at java.awt.Window.processWindowEvent(Window.java:1868)
   at javax.swing.JDialog.processWindowEvent(JDialog.java:628)
   at java.awt.Window.processEvent(Window.java:1823)
   at java.awt.Component.dispatchEventImpl(Component.java:4714)
   at java.awt.Container.dispatchEventImpl(Container.java:2143)
   at java.awt.Window.dispatchEventImpl(Window.java:2478)
   at java.awt.Component.dispatchEvent(Component.java:4544)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:635)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:137)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)