java.lang.NullPointerException
        at org.netbeans.modules.apisupport.project.Util.findSubElements(Util.java:96)
        at org.netbeans.modules.apisupport.project.SubprojectProviderImpl.getSubProjects(SubprojectProviderImpl.java:52)
        at org.netbeans.modules.project.ui.ProjectChooserAccessory.addSubprojects(ProjectChooserAccessory.java:317)
        at org.netbeans.modules.project.ui.ProjectChooserAccessory.fillSubProjectsModel(ProjectChooserAccessory.java:268)
        at org.netbeans.modules.project.ui.ProjectChooserAccessory.propertyChange(ProjectChooserAccessory.java:185)
        at javax.swing.event.SwingPropertyChangeSupport.firePropertyChange(SwingPropertyChangeSupport.java:264)
        at javax.swing.event.SwingPropertyChangeSupport.firePropertyChange(SwingPropertyChangeSupport.java:232)
        at javax.swing.JComponent.firePropertyChange(JComponent.java:3819)
        at javax.swing.JFileChooser.setSelectedFile(JFileChooser.java:454)
        at com.sun.java.swing.plaf.windows.WindowsFileChooserUI$14.valueChanged(WindowsFileChooserUI.java:1197)
        at javax.swing.JList.fireSelectionValueChanged(JList.java:1321)
        at javax.swing.JList$ListSelectionHandler.valueChanged(JList.java:1335)
        at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:187)
        at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:157)
        at javax.swing.DefaultListSelectionModel.setValueIsAdjusting(DefaultListSelectionModel.java:554)
        at javax.swing.JList.setValueIsAdjusting(JList.java:1675)
        at javax.swing.plaf.basic.BasicListUI$MouseInputHandler.mouseReleased(BasicListUI.java:1371)
        at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:232)
        at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:231)
        at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:231)
        at java.awt.Component.processMouseEvent(Component.java:5100)
        at java.awt.Component.processEvent(Component.java:4897)
        at java.awt.Container.processEvent(Container.java:1569)
        at java.awt.Component.dispatchEventImpl(Component.java:3615)
        at java.awt.Container.dispatchEventImpl(Container.java:1627)
        at java.awt.Component.dispatchEvent(Component.java:3477)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3483)
        at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3198)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3128)
        at java.awt.Container.dispatchEventImpl(Container.java:1613)
        at java.awt.Window.dispatchEventImpl(Window.java:1606)
        at java.awt.Component.dispatchEvent(Component.java:3477)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:456)
[catch] at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:141)
        at java.awt.Dialog$1.run(Dialog.java:540)
        at java.awt.Dialog.show(Dialog.java:561)
        at javax.swing.JFileChooser.showDialog(JFileChooser.java:696)
        at javax.swing.JFileChooser.showOpenDialog(JFileChooser.java:599)
        at org.netbeans.modules.project.ui.OpenProjectAction.performAction(OpenProjectAction.java:52)
        at org.openide.util.actions.CallableSystemAction$1.run(CallableSystemAction.java:78)
        at org.openide.util.actions.CallableSystemAction.doPerformAction(CallableSystemAction.java:116)
        at org.openide.util.actions.CallableSystemAction.actionPerformed(CallableSystemAction.java:76)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1786)
        at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(AbstractButton.java:1839)
        at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:420)
        at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:258)
        at javax.swing.AbstractButton.doClick(AbstractButton.java:289)
        at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1113)
        at javax.swing.plaf.basic.BasicMenuItemUI$MouseInputHandler.mouseReleased(BasicMenuItemUI.java:943)
        at java.awt.Component.processMouseEvent(Component.java:5100)
        at java.awt.Component.processEvent(Component.java:4897)
        at java.awt.Container.processEvent(Container.java:1569)
        at java.awt.Component.dispatchEventImpl(Component.java:3615)
        at java.awt.Container.dispatchEventImpl(Container.java:1627)
        at java.awt.Component.dispatchEvent(Component.java:3477)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3483)
        at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3198)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3128)
        at java.awt.Container.dispatchEventImpl(Container.java:1613)
        at java.awt.Window.dispatchEventImpl(Window.java:1606)
        at java.awt.Component.dispatchEvent(Component.java:3477)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:456)
        at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:145)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:137)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:100)