java.lang.NullPointerException
        at org.netbeans.modules.uml.codegen.action.GenerateCodeAction.enable(GenerateCodeAction.java:438)
        at org.openide.util.actions.NodeAction.isEnabled(NodeAction.java:202)
        at org.netbeans.modules.uml.ui.swing.drawingarea.ADDrawingAreaControl.addAddinMenus(ADDrawingAreaControl.java:10065)
        at org.netbeans.modules.uml.ui.swing.drawingarea.ADDrawingAreaControl.menuAboutToShow(ADDrawingAreaControl.java:10029)
        at org.netbeans.modules.uml.ui.swing.drawingarea.ADDrawingAreaControl.showPopupMenu(ADDrawingAreaControl.java:9793)
        at org.netbeans.modules.uml.ui.swing.drawingarea.ADDrawingAreaControl.access$1400(ADDrawingAreaControl.java:380)
        at org.netbeans.modules.uml.ui.swing.drawingarea.ADDrawingAreaControl$MouseHandler.mousePressed(ADDrawingAreaControl.java:9900)
        at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:263)
        at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:262)
        at java.awt.Component.processMouseEvent(Component.java:6035)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3265)
        at java.awt.Component.processEvent(Component.java:5803)
        at java.awt.Container.processEvent(Container.java:2058)
        at java.awt.Component.dispatchEventImpl(Component.java:4410)
        at java.awt.Container.dispatchEventImpl(Container.java:2116)
        at java.awt.Component.dispatchEvent(Component.java:4240)
        at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4322)
        at java.awt.LightweightDispatcher.processMouseEvent(LightweightDispatcher.java:3983)
        at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:3916)
        at java.awt.Container.dispatchEventImpl(Container.java:2102)
        at java.awt.Window.dispatchEventImpl(Window.java:2429)
        at java.awt.Component.dispatchEvent(Component.java:4240)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)