Jdeveloper Issues

Error:

**an unexpected servere error has occured in Jdeveloper** 

**The program may be unstable, which could result in data loss. Decide how you want to proceed and click OK**

and Error Details 
 oracle.ide.model.IdeSubject notifyObservers
SEVERE: Exception while updating observer[0]: oracle.bm.commonIde.ProjectObserver@156ee8e
java.lang.NullPointerException
at oracle.ide.Ide.getDefaultProject(Ide.java:487)
at oracle.bm.commonIde.ProjectObserver.update(ProjectObserver.java:57)
at oracle.ide.model.IdeSubject.notifyObservers(IdeSubject.java:98)
at oracle.ide.model.Node.notifyObservers(Node.java:786)
at oracle.ide.model.UpdateMessage.fireObjectOpened(UpdateMessage.java:673)
at oracle.ide.model.Node$14$1.run(Node.java:2878)
at oracle.ide.model.NodeListener.invokeLaterIfNeeded(NodeListener.java:158)
at oracle.ide.model.Node$14.nodeOpened(Node.java:2869)
at oracle.ide.model.Node$5.run(Node.java:2531)
at oracle.ide.model.Node.fireNodeEvent(Node.java:2467)
at oracle.ide.model.Node.fireNodeOpened(Node.java:2529)
at oracle.ide.model.Node.open(Node.java:988)
at oracle.ide.model.Node.open(Node.java:922)
at oracle.ideri.navigator.DefaultNavigatorWindow.openDataNodes(DefaultNavigatorWindow.java:1237)
at oracle.ideri.navigator.DefaultNavigatorWindow.restoreExpansionState(DefaultNavigatorWindow.java:1215)
at oracle.ideri.navigator.DefaultNavigatorWindow.loadLayout(DefaultNavigatorWindow.java:619)
at oracle.ide.navigator.ProjectNavigatorWindow.loadLayout(ProjectNavigatorWindow.java:391)
at oracle.ide.docking.DrawerWindow.loadLayout(DrawerWindow.java:640)
at oracle.ide.navigator.ApplicationNavigatorWindow.loadLayout(ApplicationNavigatorWindow.java:1174)
at oracle.ideimpl.docking.DockStationImpl.loadViewData(DockStationImpl.java:1353)
at oracle.ideimpl.docking.TitledPanel.loadClientLayout(TitledPanel.java:1376)
at oracle.ideimpl.docking.TitledPanel.loadLayout(TitledPanel.java:1714)
at oracle.ideimpl.docking.TitledPanelXMLDockLayoutPersistence.loadComponent(TitledPanelXMLDockLayoutPersistence.java:29)
at oracle.ideimpl.controls.dockLayout.DockLayoutInfoLeaf.loadLayout(DockLayoutInfoLeaf.java:123)
at oracle.ideimpl.controls.dockLayout.AbstractDockLayoutInfoNode.loadLayout(AbstractDockLayoutInfoNode.java:631)
at oracle.ideimpl.controls.dockLayout.AbstractDockLayoutInfoNode.loadLayout(AbstractDockLayoutInfoNode.java:628)
at oracle.ideimpl.controls.dockLayout.AbstractDockLayoutInfoNode.loadLayout(AbstractDockLayoutInfoNode.java:628)
at oracle.ideimpl.controls.dockLayout.AbstractDockLayoutInfoNode.loadLayout(AbstractDockLayoutInfoNode.java:614)
at oracle.ideimpl.controls.dockLayout.DockLayout.loadLayout(DockLayout.java:302)
at oracle.ideimpl.docking.DockStationImpl.loadLayout(DockStationImpl.java:1473)
at oracle.ideimpl.docking.DockStationListener.init(DockStationListener.java:36)
at oracle.ide.layout.Layouts.activate(Layouts.java:812)
at oracle.ide.layout.Layouts.activateLayout(Layouts.java:192)
at oracle.ideimpl.MainWindowImpl$6.runImpl(MainWindowImpl.java:728)
at oracle.javatools.util.SwingClosure$1Closure.run(SwingClosure.java:50)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:199)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
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)
............
..................................



Solution:



In Windows 7 :

1) Go to help->about->properties->ide.user.dir that location.

2) Close the Jdeveloper.

3) Delete the whole Directory of the ide.user.dir location . If you are unable to find the directory manually type and you should be able to go.

4) Now Restart the Jdeveloper .

5) This should solve the issue. If not after deleting this Directory uninstall Jdev and give clean install.

This location behaves like a cache.

- Uninstall Jdeveloper 11 g.
- Go to the system directory with the JDeveloper preferences and delete it.
(Check the location under help->about->properties->ide.user.dir)
- Re-install Jdeveloper 11g.