javax.swing.undo.CannotUndoException
	at org.netbeans.editor.BaseDocumentEvent.undo(BaseDocumentEvent.java:246)
	at org.netbeans.editor.GuardedDocumentEvent.undo(GuardedDocumentEvent.java:47)
	at javax.swing.undo.CompoundEdit.undo(CompoundEdit.java:46)
	at javax.swing.undo.CompoundEdit.undo(CompoundEdit.java:46)
	at org.netbeans.modules.xml.xam.AbstractModel$ModelUndoableEdit.undo(AbstractModel.java:555)
	at org.netbeans.modules.bpel.model.impl.BpelModelImpl$BpelModelUndoableEdit.undo(BpelModelImpl.java:798)
	at javax.swing.undo.UndoManager.undoTo(UndoManager.java:320)
	at javax.swing.undo.UndoManager.undo(UndoManager.java:398)
	at org.netbeans.modules.xml.refactoring.XMLRefactoringTransaction.rollback(XMLRefactoringTransaction.java:144)
	at org.netbeans.modules.refactoring.api.RefactoringSession.undoRefactoring(RefactoringSession.java:132)
	at org.netbeans.modules.refactoring.spi.impl.UndoManager$SessionUndoItem.undo(UndoManager.java:556)
	at org.netbeans.modules.refactoring.spi.impl.UndoManager.undo(UndoManager.java:192)
	at org.netbeans.modules.refactoring.spi.impl.UndoAction.performAction(UndoAction.java:74)
	at org.openide.util.actions.CallableSystemAction$1.run(CallableSystemAction.java:96)
	at org.netbeans.modules.openide.util.ActionsBridge$ActionRunnable.actionPerformed(ActionsBridge.java:89)
	at org.netbeans.core.ModuleActions.invokeAction(ModuleActions.java:82)
	at org.netbeans.modules.openide.actions.ActionsBridgeImpl.invokeAction(ActionsBridgeImpl.java:30)
	at org.netbeans.modules.openide.util.ActionsBridge$ActionRunnable.doRun(ActionsBridge.java:80)
	at org.netbeans.modules.openide.util.ActionsBridge$1.run(ActionsBridge.java:49)
	at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:539)
[catch] at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:964)