java.lang.NullPointerException at org.netbeans.modules.uml.drawingarea.persistence.DiagramLoader.findReturnMessage(DiagramLoader.java:1325) at org.netbeans.modules.uml.drawingarea.persistence.DiagramLoader.createSQDMessages(DiagramLoader.java:1245) at org.netbeans.modules.uml.drawingarea.persistence.DiagramLoader.access$000(DiagramLoader.java:98) at org.netbeans.modules.uml.drawingarea.persistence.DiagramLoader$1.perfomeAction(DiagramLoader.java:506) at org.netbeans.modules.uml.drawingarea.actions.AfterValidationExecutor.sceneValidated(AfterValidationExecutor.java:94) at org.netbeans.api.visual.widget.Scene.validate(Scene.java:420) at org.netbeans.modules.uml.diagrams.actions.sqd.AddCarFprPresentationElementAction.perfomeAction(AddCarFprPresentationElementAction.java:76) at org.netbeans.modules.uml.drawingarea.actions.AfterValidationExecutor.sceneValidated(AfterValidationExecutor.java:94) at org.netbeans.api.visual.widget.Scene.validate(Scene.java:420) at org.netbeans.modules.uml.diagrams.actions.sqd.AddCarFprPresentationElementAction.perfomeAction(AddCarFprPresentationElementAction.java:76) at org.netbeans.modules.uml.drawingarea.actions.AfterValidationExecutor.sceneValidated(AfterValidationExecutor.java:94) at org.netbeans.api.visual.widget.Scene.validate(Scene.java:420) at org.netbeans.modules.uml.diagrams.actions.sqd.AddCarFprPresentationElementAction.perfomeAction(AddCarFprPresentationElementAction.java:76) at org.netbeans.modules.uml.drawingarea.actions.AfterValidationExecutor.sceneValidated(AfterValidationExecutor.java:94) at org.netbeans.api.visual.widget.Scene.validate(Scene.java:420) at org.netbeans.modules.uml.diagrams.actions.sqd.AddCarFprPresentationElementAction.perfomeAction(AddCarFprPresentationElementAction.java:76) at org.netbeans.modules.uml.drawingarea.actions.AfterValidationExecutor.sceneValidated(AfterValidationExecutor.java:94) at org.netbeans.api.visual.widget.Scene.validate(Scene.java:420) at org.netbeans.modules.uml.diagrams.actions.sqd.AddCarFprPresentationElementAction.perfomeAction(AddCarFprPresentationElementAction.java:76) at org.netbeans.modules.uml.drawingarea.actions.AfterValidationExecutor.sceneValidated(AfterValidationExecutor.java:94) at org.netbeans.api.visual.widget.Scene.validate(Scene.java:420) at org.netbeans.modules.uml.diagrams.actions.sqd.AddCarFprPresentationElementAction.perfomeAction(AddCarFprPresentationElementAction.java:76) at org.netbeans.modules.uml.drawingarea.actions.AfterValidationExecutor.sceneValidated(AfterValidationExecutor.java:94) at org.netbeans.api.visual.widget.Scene.validate(Scene.java:420) at org.netbeans.modules.uml.diagrams.actions.sqd.AddCarFprPresentationElementAction.perfomeAction(AddCarFprPresentationElementAction.java:76) at org.netbeans.modules.uml.drawingarea.actions.AfterValidationExecutor.sceneValidated(AfterValidationExecutor.java:94) at org.netbeans.api.visual.widget.Scene.validate(Scene.java:420) at org.netbeans.api.visual.widget.SceneComponent.addNotify(SceneComponent.java:88) at java.awt.Container.addNotify(Container.java:2560) at javax.swing.JComponent.addNotify(JComponent.java:4683) at java.awt.Container.addNotify(Container.java:2560) at javax.swing.JComponent.addNotify(JComponent.java:4683) at java.awt.Container.addNotify(Container.java:2560) at javax.swing.JComponent.addNotify(JComponent.java:4683) at java.awt.Container.addNotify(Container.java:2560) at javax.swing.JComponent.addNotify(JComponent.java:4683) at java.awt.Container.addNotify(Container.java:2560) at javax.swing.JComponent.addNotify(JComponent.java:4683) at java.awt.Container.addImpl(Container.java:1039) at java.awt.Container.add(Container.java:348) at org.netbeans.swing.tabcontrol.plaf.StackLayout.showComponent(StackLayout.java:75) at org.netbeans.swing.tabcontrol.plaf.DefaultTabbedContainerUI.showComponent(DefaultTabbedContainerUI.java:564) at org.netbeans.swing.tabcontrol.plaf.DefaultTabbedContainerUI$NoOpFxProvider.doFinish(DefaultTabbedContainerUI.java:1358) at org.netbeans.swing.tabcontrol.plaf.FxProvider.finish(FxProvider.java:102) at org.netbeans.swing.tabcontrol.plaf.DefaultTabbedContainerUI$NoOpFxProvider.doStart(DefaultTabbedContainerUI.java:1363) at org.netbeans.swing.tabcontrol.plaf.FxProvider.start(FxProvider.java:85) at org.netbeans.swing.tabcontrol.plaf.DefaultTabbedContainerUI.showComponentWithFxProvider(DefaultTabbedContainerUI.java:593) at org.netbeans.swing.tabcontrol.plaf.DefaultTabbedContainerUI$SelectionListener.stateChanged(DefaultTabbedContainerUI.java:1060) at org.openide.util.ChangeSupport.fireChange(ChangeSupport.java:123) at org.openide.util.ChangeSupport.fireChange(ChangeSupport.java:109) at org.netbeans.swing.tabcontrol.plaf.DefaultTabSelectionModel.indicesChanged(DefaultTabSelectionModel.java:273) at org.netbeans.swing.tabcontrol.DefaultTabDataModel.fireIndicesChanged(DefaultTabDataModel.java:492) at org.netbeans.swing.tabcontrol.DefaultTabDataModel.setTabs(DefaultTabDataModel.java:120) at org.netbeans.core.windows.view.ui.tabcontrol.TabbedAdapter.setTopComponents(TabbedAdapter.java:234) at org.netbeans.core.windows.view.ui.TabbedHandler.setTopComponents(TabbedHandler.java:158) at org.netbeans.core.windows.view.ui.AbstractModeContainer.setTopComponents(AbstractModeContainer.java:124) at org.netbeans.core.windows.view.ModeView.setTopComponents(ModeView.java:137) at org.netbeans.core.windows.view.ViewHierarchy.updateViewForAccessor(ViewHierarchy.java:254) at org.netbeans.core.windows.view.ViewHierarchy.updateViewForAccessor(ViewHierarchy.java:241) at org.netbeans.core.windows.view.ViewHierarchy.updateViewForAccessor(ViewHierarchy.java:226) at org.netbeans.core.windows.view.ViewHierarchy.updateViewForAccessor(ViewHierarchy.java:226) at org.netbeans.core.windows.view.ViewHierarchy.updateViewForAccessor(ViewHierarchy.java:226) at org.netbeans.core.windows.view.ViewHierarchy.updateViewHierarchy(ViewHierarchy.java:143) at org.netbeans.core.windows.view.DefaultView.changeGUI(DefaultView.java:149) at org.netbeans.core.windows.ViewRequestor.dispatchRequest(ViewRequestor.java:269) at org.netbeans.core.windows.ViewRequestor.processRequest(ViewRequestor.java:245) at org.netbeans.core.windows.ViewRequestor.postRequest(ViewRequestor.java:183) at org.netbeans.core.windows.ViewRequestor.scheduleRequest(ViewRequestor.java:123) at org.netbeans.core.windows.Central.addModeOpenedTopComponent(Central.java:757) at org.netbeans.core.windows.ModeImpl.addOpenedTopComponent(ModeImpl.java:311) at org.netbeans.core.windows.WindowManagerImpl.topComponentOpenAtTabPosition(WindowManagerImpl.java:1104) at org.netbeans.core.windows.WindowManagerImpl.topComponentOpen(WindowManagerImpl.java:1071) at org.openide.windows.TopComponent.open(TopComponent.java:384) at org.openide.windows.TopComponent.open(TopComponent.java:375) at org.netbeans.modules.uml.drawingarea.UMLDiagramManager$ShowTopComponentGroup.show(UMLDiagramManager.java:976) at org.netbeans.modules.uml.drawingarea.UMLDiagramManager.showDiagram(UMLDiagramManager.java:541) at org.netbeans.modules.uml.drawingarea.UMLDiagramManager.showDiagram(UMLDiagramManager.java:512) at org.netbeans.modules.uml.drawingarea.UMLDiagramManager.openDiagram(UMLDiagramManager.java:133) at org.netbeans.modules.uml.ui.products.ad.projecttreedefaultengine.ADProjectTreeEngine.handleDoubleClick(ADProjectTreeEngine.java:3494) at org.netbeans.modules.uml.ui.products.ad.projecttreedefaultengine.ADProjectTreeEngine.onNodeDoubleClick(ADProjectTreeEngine.java:3435) at org.netbeans.modules.uml.ui.products.ad.projecttreedefaultengine.ADProjectTreeEngine$ProjectTreeListener.onDoubleClick(ADProjectTreeEngine.java:3751) at sun.reflect.NativeMethodAccessorImpl.invoke0(NativeMethodAccessorImpl.java:0) 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.netbeans.modules.uml.core.eventframework.EventFunctor.invokeMethod(EventFunctor.java:237) at org.netbeans.modules.uml.core.eventframework.EventFunctor.execute(EventFunctor.java:123) at org.netbeans.modules.uml.core.eventframework.EventManager.notifyListeners(EventManager.java:184) at org.netbeans.modules.uml.ui.controls.projecttree.ProjectTreeEventDispatcherImpl.fireDoubleClick(ProjectTreeEventDispatcherImpl.java:382) at org.netbeans.modules.uml.project.ui.nodes.UMLElementNode$ModelElementOpen.open(UMLElementNode.java:918) at org.openide.actions.OpenAction.performAction(OpenAction.java:81) at org.openide.util.actions.NodeAction$DelegateAction$1.run(NodeAction.java:581) at org.netbeans.modules.openide.util.ActionsBridge.doPerformAction(ActionsBridge.java:77) at org.openide.util.actions.NodeAction$DelegateAction.actionPerformed(NodeAction.java:577) at org.openide.explorer.view.TreeView$PopupSupport.mouseClicked(TreeView.java:1492) at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:253) at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:252) at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:252) at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:252) at java.awt.Component.processMouseEvent(Component.java:6137) at javax.swing.JComponent.processMouseEvent(JComponent.java:3265) at java.awt.Component.processEvent(Component.java:5899) at java.awt.Container.processEvent(Container.java:2023) at java.awt.Component.dispatchEventImpl(Component.java:4501) at java.awt.Container.dispatchEventImpl(Container.java:2081) at java.awt.Component.dispatchEvent(Component.java:4331) at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4301) at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:3974) at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:3895) at java.awt.Container.dispatchEventImpl(Container.java:2067) at java.awt.Window.dispatchEventImpl(Window.java:2458) at java.awt.Component.dispatchEvent(Component.java:4331) at java.awt.EventQueue.dispatchEvent(EventQueue.java:599) at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:104) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161) at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)