Win32Exception: Invalid window handle --NativeErrorCode: 1400 StackTrace: at MS.Internal.PointUtil.ClientToScreen(Point pointClient, PresentationSource presentationSource) at System.Windows.Input.MouseDevice.GlobalHitTest(Boolean clientUnits, Point pt, PresentationSource inputSource, IInputElement& enabledHit, IInputElement& originalHit) at System.Windows.Input.MouseDevice.PreNotifyInput(Object sender, NotifyInputEventArgs e) at System.Windows.Input.InputManager.ProcessStagingArea() at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input) at System.Windows.Input.MouseDevice.Synchronize() at System.Windows.Input.InputManager.HitTestInvalidatedAsyncCallback(Object arg) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)