Why do I receive an error about java.lang.​​NullPoint​e​rExcepti​on on Windows 7?

Why I receive this message when I open the matlab?

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException at com.mathworks.toolstrip.factory.TSToolSetContents$Tool.addChild(TSToolSetContents.java:360) at com.mathworks.toolstrip.factory.TSToolSetContents$Tool.access$3500(TSToolSetContents.java:123) at com.mathworks.toolstrip.factory.TSToolSetContents.addToParent(TSToolSetContents.java:1085) at com.mathworks.toolstrip.factory.TSToolSetContents.addDependents(TSToolSetContents.java:1058) at com.mathworks.toolstrip.factory.TSToolSetContents.resolveDependencies(TSToolSetContents.java:914) at com.mathworks.toolstrip.factory.TSRegistry.addToolSetContents(TSRegistry.java:100) at com.mathworks.mde.desk.ContributedToolsLoader$2$1.run(ContributedToolsLoader.java:45) at java.awt.event.InvocationEvent.dispatch(Unknown Source) at java.awt.EventQueue.dispatchEventImpl(Unknown Source) at java.awt.EventQueue.access$200(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source) at java.awt.EventQueue.dispatchEvent(Unknown Source) at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.run(Unknown Source) >>