java.lang.NullPointerException at org.eclipse.gef.ui.actions.UndoAction.calculateEnabled(UndoAction.java:55) at org.eclipse.gef.ui.actions.WorkbenchPartAction.isEnabled(WorkbenchPartAction.java:123) at org.eclipse.ui.actions.RetargetAction.setActionHandler(RetargetAction.java:273) at org.eclipse.ui.actions.LabelRetargetAction.setActionHandler(LabelRetargetAction.java:91) at org.eclipse.ui.actions.RetargetAction.propagateChange(RetargetAction.java:211) at org.eclipse.ui.actions.LabelRetargetAction.propagateChange(LabelRetargetAction.java:73) at org.eclipse.ui.actions.RetargetAction$1.propertyChange(RetargetAction.java:61) at org.eclipse.ui.SubActionBars.firePropertyChange(SubActionBars.java:292) at org.eclipse.ui.SubActionBars.fireActionHandlersChanged(SubActionBars.java:274) at org.eclipse.ui.SubActionBars.updateActionBars(SubActionBars.java:613) at org.eclipse.graphiti.ui.internal.parts.directedit.GFDirectEditManager.bringDown(GFDirectEditManager.java:314) at org.eclipse.gef.tools.DirectEditManager$5.partDeactivated(DirectEditManager.java:306) at org.eclipse.gef.editparts.AbstractEditPart.fireDeactivated(AbstractEditPart.java:413) at org.eclipse.gef.editparts.AbstractEditPart.deactivate(AbstractEditPart.java:298) at org.eclipse.gef.editparts.AbstractGraphicalEditPart.deactivate(AbstractGraphicalEditPart.java:354) at org.eclipse.graphiti.ui.internal.parts.ShapeEditPart.deactivate(ShapeEditPart.java:134) at org.eclipse.gef.editparts.AbstractEditPart.removeChild(AbstractEditPart.java:879) at org.eclipse.graphiti.ui.internal.parts.ShapeEditPart.deleteChildAndRefresh(ShapeEditPart.java:144) at org.eclipse.graphiti.ui.internal.parts.PictogramElementDelegate.refreshFigureForEditPart(PictogramElementDelegate.java:347) at org.eclipse.graphiti.ui.internal.parts.ShapeEditPart.refreshVisuals(ShapeEditPart.java:664) at org.eclipse.gef.editparts.AbstractEditPart.refresh(AbstractEditPart.java:725) at org.eclipse.gef.editparts.AbstractGraphicalEditPart.refresh(AbstractGraphicalEditPart.java:644) at org.eclipse.graphiti.ui.internal.parts.ShapeEditPart.refresh(ShapeEditPart.java:559) at org.eclipse.graphiti.ui.editor.DefaultRefreshBehavior.internalRefreshEditPart(DefaultRefreshBehavior.java:256) at org.eclipse.graphiti.ui.internal.editor.DiagramRefreshJob.runInUIThread(DiagramRefreshJob.java:106) at org.eclipse.graphiti.ui.internal.editor.DiagramChangeListener.resourceSetChanged(DiagramChangeListener.java:150) at org.eclipse.emf.transaction.impl.TransactionalEditingDomainImpl$1.run(TransactionalEditingDomainImpl.java:781) at org.eclipse.emf.transaction.impl.TransactionalEditingDomainImpl.runExclusive(TransactionalEditingDomainImpl.java:328) at org.eclipse.emf.transaction.impl.TransactionalEditingDomainImpl.postcommit(TransactionalEditingDomainImpl.java:771) at org.eclipse.emf.transaction.impl.TransactionalEditingDomainImpl.deactivate(TransactionalEditingDomainImpl.java:543) at org.eclipse.emf.transaction.impl.TransactionImpl.close(TransactionImpl.java:712) at org.eclipse.emf.transaction.impl.TransactionImpl.commit(TransactionImpl.java:474) at org.eclipse.emf.workspace.AbstractEMFOperation.execute(AbstractEMFOperation.java:155) at org.eclipse.core.commands.operations.DefaultOperationHistory.execute(DefaultOperationHistory.java:513) at org.eclipse.emf.workspace.impl.WorkspaceCommandStackImpl.doExecute(WorkspaceCommandStackImpl.java:208) at org.eclipse.emf.transaction.impl.AbstractTransactionalCommandStack.execute(AbstractTransactionalCommandStack.java:165) at org.eclipse.graphiti.ui.internal.editor.GFWorkspaceCommandStackImpl.execute(GFWorkspaceCommandStackImpl.java:84) at org.eclipse.graphiti.ui.internal.editor.GFCommandStack.execute(GFCommandStack.java:124) at org.eclipse.graphiti.ui.internal.policy.DefaultDirectEditPolicy.getDirectEditCommand(DefaultDirectEditPolicy.java:141) at org.eclipse.gef.editpolicies.DirectEditPolicy.getCommand(DirectEditPolicy.java:59) at org.eclipse.gef.editparts.AbstractEditPart.getCommand(AbstractEditPart.java:502) at org.eclipse.gef.tools.DirectEditManager.commit(DirectEditManager.java:144) at org.eclipse.gef.tools.DirectEditManager$4.applyEditorValue(DirectEditManager.java:291) at org.eclipse.jface.viewers.CellEditor$1.run(CellEditor.java:335) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:49) at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175) at org.eclipse.jface.viewers.CellEditor.fireApplyEditorValue(CellEditor.java:333) at org.eclipse.jface.viewers.CellEditor.focusLost(CellEditor.java:718) at org.eclipse.graphiti.ui.internal.parts.directedit.TextCellEditor.access$6(TextCellEditor.java:1) at org.eclipse.graphiti.ui.internal.parts.directedit.TextCellEditor$5.focusLost(TextCellEditor.java:196) at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:143) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1077) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1058) at org.eclipse.swt.widgets.Control.sendFocusEvent(Control.java:2822) at org.eclipse.swt.widgets.Widget.wmKillFocus(Widget.java:1921) at org.eclipse.swt.widgets.Control.WM_KILLFOCUS(Control.java:4900) at org.eclipse.swt.widgets.Control.windowProc(Control.java:4562) at org.eclipse.swt.widgets.Text.windowProc(Text.java:2254) at org.eclipse.swt.widgets.Display.windowProc(Display.java:4985) at org.eclipse.swt.internal.win32.OS.SetFocus(Native Method) at org.eclipse.swt.widgets.Control.forceFocus(Control.java:1098) at org.eclipse.gef.ui.parts.DomainEventDispatcher.dispatchMousePressed(DomainEventDispatcher.java:346) at org.eclipse.draw2d.LightweightSystem$EventHandler.mouseDown(LightweightSystem.java:523) at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:191) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053) at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4165) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3754) at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2701) at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2665) at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2499) at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:679) at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332) at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:668) at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149) at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:123) at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:344) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622) at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577) at org.eclipse.equinox.launcher.Main.run(Main.java:1410) at org.eclipse.equinox.launcher.Main.main(Main.java:1386)