java.lang.AssertionError
   at org.netbeans.modules.uml.drawingarea.UMLDiagramTopComponent.<init>(UMLDiagramTopComponent.java:258)
   at org.netbeans.modules.uml.drawingarea.UMLDiagramManager.showDiagram(UMLDiagramManager.java:511)
   at org.netbeans.modules.uml.drawingarea.UMLDiagramManager.openDiagram(UMLDiagramManager.java:135)
   at org.netbeans.modules.uml.ui.support.DiagramBuilder.navigateToTarget(DiagramBuilder.java:110)
   at org.netbeans.modules.uml.ui.support.DiagramBuilder.navigateToFirstTarget(DiagramBuilder.java:163)
   at org.netbeans.modules.uml.ui.support.DiagramAndPresentationNavigator.navigateToPresentationTarget(DiagramAndPresentationNavigator.java:134)
   at org.netbeans.modules.uml.integration.finddialog.FindController.findInDiagrams(FindController.java:1023)
   at org.netbeans.modules.uml.integration.finddialog.FindController.navigateToElement(FindController.java:422)
   at org.netbeans.modules.uml.integration.finddialog.FindUtilities.onDblClickFindResults(FindUtilities.java:280)
   at org.netbeans.modules.uml.integration.finddialog.ui.FindDialogUI.onDblClickFindResults(FindDialogUI.java:882)
   at org.netbeans.modules.uml.integration.finddialog.ui.JFindTable$FindMouseHandler.mousePressed(JFindTable.java:128)
   at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:263)
   at java.awt.Component.processMouseEvent(Component.java:6260)
   at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
   at java.awt.Component.processEvent(Component.java:6028)
   at java.awt.Container.processEvent(Container.java:2041)
   at java.awt.Component.dispatchEventImpl(Component.java:4630)
   at java.awt.Container.dispatchEventImpl(Container.java:2099)
   at java.awt.Component.dispatchEvent(Component.java:4460)
   at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4574)
   at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:4235)
   at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4168)
   at java.awt.Container.dispatchEventImpl(Container.java:2085)
   at java.awt.Window.dispatchEventImpl(Window.java:2478)
   at java.awt.Component.dispatchEvent(Component.java:4460)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:130)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:178)
   at java.awt.Dialog$1.run(Dialog.java:1046)
   at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:130)
   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)