InvalidOperationException: Cannot set Visibility to Visible or call Show, ShowDialog, Close, or WindowInteropHelper.EnsureHandle while a Window is closing.
StackTrace:
   at System.Windows.Window.VerifyNotClosing()
   at System.Windows.Window.InternalClose(Boolean shutdown, Boolean ignoreCancel)
   at System.Windows.Window.OnDeactivated(EventArgs e)
   at System.Windows.Window.HandleActivate(Boolean windowActivated)
   at System.Windows.Window.WmActivate(IntPtr wParam)
   at System.Windows.Window.WindowFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at System.Windows.Interop.HwndSource.PublicHooksFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
   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)