java.lang.NullPointerException
        at org.netbeans.modules.j2ee.impl.ServerRegistryImpl.selectInstance(ServerRegistryImpl.java:211)
        at org.netbeans.modules.j2ee.impl.ServerRegistryImpl.getDefaultWebInstance(ServerRegistryImpl.java:237)
        at org.netbeans.modules.j2ee.ui.ServerRegistryNode.createKeyNodes(ServerRegistryNode.java:104)
        at org.netbeans.modules.j2ee.ui.ServerRegistryNode$RegistryChildren.createNodes(ServerRegistryNode.java:272)
        at org.openide.nodes.Children$Keys$KE.nodes(Children.java:1826)
        at org.openide.nodes.ChildrenArray.nodesFor(ChildrenArray.java:125)
        at org.openide.nodes.Children$Info.nodes(Children.java:929)
        at org.openide.nodes.Children.updateAdd(Children.java:737)
        at org.openide.nodes.Children.setEntries(Children.java:526)
        at org.openide.nodes.Children$3.run(Children.java:1719)
        at org.openide.util.Mutex.leave(Mutex.java:604)
        at org.openide.util.Mutex.readAccess(Mutex.java:173)
        at org.openide.explorer.view.VisualizerNode.getChildren(VisualizerNode.java:147)
        at org.openide.explorer.view.VisualizerNode.getChildCount(VisualizerNode.java:187)
        at javax.swing.tree.DefaultTreeModel.getChildCount(DefaultTreeModel.java:168)
        at javax.swing.tree.VariableHeightLayoutCache$TreeStateNode.expand(VariableHeightLayoutCache.java:1461)
        at javax.swing.tree.VariableHeightLayoutCache$TreeStateNode.expand(VariableHeightLayoutCache.java:1270)
        at javax.swing.tree.VariableHeightLayoutCache.ensurePathIsExpanded(VariableHeightLayoutCache.java:966)
        at javax.swing.tree.VariableHeightLayoutCache.setExpandedState(VariableHeightLayoutCache.java:164)
        at javax.swing.plaf.basic.BasicTreeUI.updateExpandedDescendants(BasicTreeUI.java:1494)
        at javax.swing.plaf.basic.BasicTreeUI$TreeExpansionHandler.treeExpanded(BasicTreeUI.java:2312)
        at javax.swing.JTree.fireTreeExpanded(JTree.java:2238)
        at javax.swing.JTree.setExpandedState(JTree.java:3009)
        at javax.swing.JTree.expandPath(JTree.java:1744)
        at javax.swing.plaf.basic.BasicTreeUI.toggleExpandState(BasicTreeUI.java:2093)
        at javax.swing.plaf.basic.BasicTreeUI.handleExpandControlClick(BasicTreeUI.java:2080)
        at javax.swing.plaf.basic.BasicTreeUI.checkForClickInExpandControl(BasicTreeUI.java:2034)
        at javax.swing.plaf.basic.BasicTreeUI$MouseHandler.handleSelection(BasicTreeUI.java:2809)
        at javax.swing.plaf.basic.BasicTreeUI$MouseHandler.mousePressed(BasicTreeUI.java:2779)
        at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:218)
        at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:217)
        at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:217)
        at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:217)
        at java.awt.Component.processMouseEvent(Component.java:5018)
        at java.awt.Component.processEvent(Component.java:4818)
        at java.awt.Container.processEvent(Container.java:1380)
        at java.awt.Component.dispatchEventImpl(Component.java:3526)
        at java.awt.Container.dispatchEventImpl(Container.java:1437)
        at java.awt.Component.dispatchEvent(Component.java:3367)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3214)
        at java.awt.LightweightDispatcher.processMouseEvent(Container.java:2926)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:2859)
        at java.awt.Container.dispatchEventImpl(Container.java:1423)
        at java.awt.Window.dispatchEventImpl(Window.java:1566)
        at java.awt.Component.dispatchEvent(Component.java:3367)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:445)
        at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:190)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:144)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:130)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:98)