java.lang.IllegalStateException: Cannot modify resource set without a write transaction
	at org.eclipse.emf.transaction.impl.TransactionChangeRecorder.assertWriting(TransactionChangeRecorder.java:348)
	at org.eclipse.emf.transaction.impl.TransactionChangeRecorder.appendNotification(TransactionChangeRecorder.java:302)
	at org.eclipse.emf.transaction.impl.TransactionChangeRecorder.processObjectNotification(TransactionChangeRecorder.java:284)
	at org.eclipse.emf.transaction.impl.TransactionChangeRecorder.notifyChanged(TransactionChangeRecorder.java:240)
	at org.eclipse.emf.common.notify.impl.BasicNotifierImpl.eNotify(BasicNotifierImpl.java:374)
	at org.eclipse.emf.common.notify.impl.NotificationImpl.dispatch(NotificationImpl.java:1027)
	at org.eclipse.graphiti.mm.pictograms.impl.ShapeImpl.setContainer(ShapeImpl.java:109)
	at org.eclipse.graphiti.internal.services.impl.PeServiceImpl.createContainerShape(PeServiceImpl.java:152)
	at org.eclipse.jpt.jpadiagrameditor.ui.internal.feature.AddJPAEntityFeature$PeUtilFacade.createContainerShape(AddJPAEntityFeature.java:333)
	at org.eclipse.jpt.jpadiagrameditor.ui.internal.feature.AddJPAEntityFeature.add(AddJPAEntityFeature.java:140)
	at org.eclipse.graphiti.internal.command.AddFeatureCommandWithContext.execute(AddFeatureCommandWithContext.java:76)
	at org.eclipse.graphiti.ui.internal.command.GefCommandWrapper.execute(GefCommandWrapper.java:51)
	at org.eclipse.gef.commands.CommandStack.execute(CommandStack.java:199)
	at org.eclipse.graphiti.ui.editor.DiagramEditor.executeFeature(DiagramEditor.java:1945)
	at org.eclipse.graphiti.features.impl.AbstractFeatureProvider.addIfPossible(AbstractFeatureProvider.java:331)
	at org.eclipse.graphiti.ui.internal.command.AddModelObjectCommand.execute(AddModelObjectCommand.java:115)
	at org.eclipse.gef.commands.CommandStack.execute(CommandStack.java:199)
	at org.eclipse.gef.dnd.AbstractTransferDropTargetListener.handleDrop(AbstractTransferDropTargetListener.java:339)
	at org.eclipse.graphiti.ui.internal.dnd.ObjectsTransferDropTargetListener.handleDrop(ObjectsTransferDropTargetListener.java:42)
	at org.eclipse.gef.dnd.AbstractTransferDropTargetListener.drop(AbstractTransferDropTargetListener.java:183)
	at org.eclipse.jface.util.DelegatingDropAdapter$3.run(DelegatingDropAdapter.java:211)
	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.util.DelegatingDropAdapter.drop(DelegatingDropAdapter.java:209)
	at org.eclipse.swt.dnd.DNDListener.handleEvent(DNDListener.java:90)
	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:1062)
	at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:774)
	at org.eclipse.swt.dnd.DropTarget.Drop(DropTarget.java:456)
	at org.eclipse.swt.dnd.DropTarget.Drop_64(DropTarget.java:392)
	at org.eclipse.swt.dnd.DropTarget$3.method6(DropTarget.java:260)
	at org.eclipse.swt.internal.ole.win32.COMObject.callback6(COMObject.java:119)
	at org.eclipse.swt.internal.ole.win32.COM.DoDragDrop(Native Method)
	at org.eclipse.swt.dnd.DragSource.drag(DragSource.java:363)
	at org.eclipse.swt.dnd.DragSource.access$0(DragSource.java:289)
	at org.eclipse.swt.dnd.DragSource$1.handleEvent(DragSource.java:172)
	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:4169)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3758)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1021)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:915)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:86)
	at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:585)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:540)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:124)
	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:353)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:180)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1438)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1414)