Windows Phone 8 error on fresh application

Question

i am using visual studio 2012 n windows 8 enterprise edition to create a windows phone 8 application! as i create a fresh application and want to run it just to see if it works, this error pops up instantly!

    System.NullReferenceException
Object reference not set to an instance of an object.
   at Microsoft.Expression.DesignHost.Isolation.Remoting.STAMarshaler.WaitForCompletion(NestedCallContext nestedCallContext, BlockingCall call, WaitHandle timeoutSignal)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.STAMarshaler.MarshalOutSynchronous(Action action, Int32 targetApartmentId, WaitHandle aborted, WaitHandle timeoutSignal)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.STAMarshaler.MarshalOut(Action action, Int32 targetApartmentId, WaitHandle aborted, CallSynchronizationMode syncMode, WaitHandle timeoutSignal)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.ThreadMarshaler.MarshalOut[TValue](RemoteHandle`1 targetObject, Action action, CallSynchronizationMode syncMode)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.ThreadMarshaler.MarshalOut[TResult,TValue](RemoteHandle`1 targetObject, Func`2 func, CallSynchronizationMode syncMode)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.LocalDesignerService.CreateDesignerImpl(IHostSourceItem item, IHostTextEditor editor, RemoteCancellationToken remoteCancelToken)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.LocalDesignerService.<>c__DisplayClass12.<Microsoft.Expression.DesignHost.IDesignerService.CreateDesigner>b__11(RemoteCancellationToken remoteToken)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.LocalDesignerService.CallWithCancellation[TResult](CancellationToken cancelToken, Func`2 func)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.LocalDesignerService.Microsoft.Expression.DesignHost.IDesignerService.CreateDesigner(IHostSourceItem item, IHostTextEditor editor, CancellationToken cancelToken)
   at Microsoft.Expression.DesignHost.IsolatedDesignerService.IsolatedDesignerView.CreateDesignerViewInfo(CancellationToken cancelToken)

System.NullReferenceException
Object reference not set to an instance of an object.

Server stack trace: 
   at Microsoft.Expression.DesignHost.Isolation.Remoting.STAMarshaler.WaitForCompletion(NestedCallContext nestedCallContext, BlockingCall call, WaitHandle timeoutSignal)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.STAMarshaler.MarshalIn(Action action, Int32 targetApartmentId)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.ThreadMarshaler.MarshalIn(IRemoteObject targetObject, Action action)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.ThreadMarshaler.MarshalIn[TResult](IRemoteObject targetObject, Func`1 func)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.RemoteDesignerService.Microsoft.Expression.DesignHost.Isolation.Remoting.IRemoteDesignerService.CreateDesigner(IRemoteHostSourceItem remoteItem, IRemoteHostTextEditor remoteEditor, IRemoteCancellationToken remoteToken)
   at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Object[]& outArgs)
   at System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMessage msg)

Exception rethrown at [0]: 
   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
   at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.IRemoteDesignerService.CreateDesigner(IRemoteHostSourceItem remoteItem, IRemoteHostTextEditor remoteEditor, IRemoteCancellationToken cancelToken)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.LocalDesignerService.<>c__DisplayClass8.<CreateDesignerImpl>b__6(IRemoteDesignerService d)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.ThreadMarshaler.<>c__DisplayClass4`2.<MarshalOut>b__3()
   at Microsoft.Expression.DesignHost.Isolation.Remoting.STAMarshaler.Call.InvokeWorker()

System.NullReferenceException
Object reference not set to an instance of an object.
   at Microsoft.Expression.Platform.PlatformService.PlatformEntry.get_PlatformCreator()
   at Microsoft.Expression.Platform.PlatformService.GetPlatformCreator(String frameworkSpec)
   at Microsoft.Expression.Platform.PlatformService.IsCompatibleFramework(FrameworkName hostFramework, FrameworkName guestFramework)
   at Microsoft.Expression.DesignSurface.Project.ProjectContextManager.GetProjectContext(IHostProject project, IPlatform platform, Boolean create)
   at Microsoft.Expression.DesignSurface.Project.ProjectContextManager.GetSourceItemContext(IHostSourceItem sourceItem)
   at Microsoft.Expression.DesignSurface.DesignerService.CreateDesigner(IHostSourceItem item, IHostTextEditor editor, CancellationToken cancelToken)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.RemoteDesignerService.<>c__DisplayClass10.<>c__DisplayClass12.<Microsoft.Expression.DesignHost.Isolation.Remoting.IRemoteDesignerService.CreateDesigner>b__f(CancellationToken cancelToken)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.RemoteDesignerService.CallWithCancellation[TResult](IRemoteCancellationToken remoteToken, Func`2 func)
   at Microsoft.Expression.DesignHost.Isolation.Remoting.RemoteDesignerService.<>c__DisplayClass10.<Microsoft.Expression.DesignHost.Isolation.Remoting.IRemoteDesignerService.CreateDesigner>b__e()
   at Microsoft.Expression.DesignHost.Isolation.Remoting.ThreadMarshaler.<>c__DisplayClass16`1.<MarshalIn>b__15()
   at Microsoft.Expression.DesignHost.Isolation.Remoting.STAMarshaler.Call.InvokeWorker()

anyone have the same problem? and maybe have a solution for this problem?

Answer 1

The problem is solved now.

Here is what I did, as suggested in the forum:

1. Uninstall WP8 SDK
2. Uninstall all instances of Silverlight SDK and Rutime.
3. Re-install WP8 SDK.

The exact order in which I fixed the VS designer problem:

1. Uninstalled all WP7 SDK:
2. Restarted computer (The designer still failed after this step)
3. Uninstalled WP8 SDK (Maybe it is enough to choose repair here, but I selected to uninstall the SDK)
4. Restarted computer
5. Installed the WP8 SDK

The designer works perfectly now :)