In a clean task definition:
- create an action
- switch to mapper
- select the new action's context
- switch to design
- delete the action
- switch to mapper
- NPE

java.lang.NullPointerException
	at org.netbeans.modules.worklist.editor.mapper.tree.model.VariableTreeModel.getChildren(VariableTreeModel.java:73)
	at org.netbeans.modules.worklist.editor.mapper.tree.MapperSwingTreeModel.getChildren(MapperSwingTreeModel.java:282)
	at org.netbeans.modules.worklist.editor.mapper.tree.MapperSwingTreeModel.isLeaf(MapperSwingTreeModel.java:109)
	at javax.swing.JTree.setModel(JTree.java:704)
	at org.netbeans.modules.soa.mappercore.Mapper.setModel(Mapper.java:557)
	at
org.netbeans.modules.worklist.editor.mapper.multiview.MapperMultiviewElement.setMapperModelInAwt(MapperMultiviewElement.java:725)
	at
org.netbeans.modules.worklist.editor.mapper.multiview.MapperMultiviewElement.setMapperModel(MapperMultiviewElement.java:716)
	at
org.netbeans.modules.worklist.editor.mapper.DesignContextControllerImpl.setMapperModel(DesignContextControllerImpl.java:451)
	at
org.netbeans.modules.worklist.editor.mapper.DesignContextControllerImpl.setContextImpl(DesignContextControllerImpl.java:363)
	at org.netbeans.modules.worklist.editor.mapper.DesignContextControllerImpl.showMapper(DesignContextControllerImpl.java:254)
	at
org.netbeans.modules.worklist.editor.mapper.multiview.MapperMultiviewElement.componentShowing(MapperMultiviewElement.java:281)
	at org.netbeans.core.multiview.MultiViewPeer.showCurrentElement(MultiViewPeer.java:294)
	at org.netbeans.core.multiview.MultiViewPeer.showCurrentElement(MultiViewPeer.java:264)
	at org.netbeans.core.multiview.MultiViewPeer$SelectionListener.selectionChanged(MultiViewPeer.java:689)
	at org.netbeans.core.multiview.MultiViewModel.fireSelectionChanged(MultiViewModel.java:243)
	at org.netbeans.core.multiview.MultiViewModel.setActiveDescription(MultiViewModel.java:115)
	at org.netbeans.core.multiview.MultiViewModel$BtnGroup.setSelected(MultiViewModel.java:293)
	at javax.swing.JToggleButton$ToggleButtonModel.setSelected(JToggleButton.java:215)
	at javax.swing.ButtonGroup.setSelected(ButtonGroup.java:139)
	at org.netbeans.core.multiview.MultiViewModel$BtnGroup.setSelected(MultiViewModel.java:289)
	at org.netbeans.core.multiview.TabsComponent$ButtonMouseListener.mousePressed(TabsComponent.java:456)
	at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:222)
	at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:221)
	at java.awt.Component.processMouseEvent(Component.java:5514)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3135)
	at java.awt.Component.processEvent(Component.java:5282)
	at java.awt.Container.processEvent(Container.java:1966)
	at java.awt.Component.dispatchEventImpl(Component.java:3984)
	at java.awt.Container.dispatchEventImpl(Container.java:2024)
	at java.awt.Component.dispatchEvent(Component.java:3819)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4212)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3889)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3822)
	at java.awt.Container.dispatchEventImpl(Container.java:2010)
	at java.awt.Window.dispatchEventImpl(Window.java:1791)
	at java.awt.Component.dispatchEvent(Component.java:3819)
[catch] at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
	at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:104)
	at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:242)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)