Bug #66109 couldn't open a EER Diagram table edit tab.

Description:
couldn't open a EER Diagram table edit tab.

----- Developer Notes -----

MySQL Workbench CE for Windows version 5.2.41  revision 9727
Configuration Directory: C:\Documents and Settings\Administrator\Application Data\MySQL\Workbench
Data Directory: C:\Program Files\MySQL\MySQL Workbench 5.2 CE
Cairo Version: 1.8.8
OS: Microsoft Windows XP Professional Service Pack 3 (build 2600)
CPU: 4x Intel(R) Core(TM) i7 CPU         950  @ 3.07GHz, 1.0 GiB RAM
Active video adapter (0): VMware SVGA II
Installed video RAM: 128 MB
Current video mode: 1920 x 1080 x 65536색
Used bit depth: 16
Driver version: 11.08.11.0000 - build-442614
Installed display drivers: vmx_fb.dll
Current user language: 한국어

Exception = System.InvalidCastException
Message = 'MySQL.Forms.MenuItemImpl' 형식 개체를 'MySQL.GUI.Workbench.Plugins.DockablePlugin' 형식으로 캐스팅할 수 없습니다.
FullText = System.InvalidCastException: 'MySQL.Forms.MenuItemImpl' 형식 개체를 'MySQL.GUI.Workbench.Plugins.DockablePlugin' 형식으로 캐스팅할 수 없습니다.
   위치: MySQL.GUI.Workbench.Plugins.DockablePlugin.GetFromFixedPtr(IntPtr ptr)
   위치: MySQL.GUI.Workbench.MainForm.ShowPlugin(IntPtr ptr)
   위치: MySQL.Forms.AppImpl.show_editor_wrapper(UInt32 native_handle)
   위치: boost.detail.function.void_function_invoker1<void (__cdecl*)(unsigned int),void,unsigned int>.invoke(function_buffer* function_ptr, UInt32 a0)
   위치: wb.ModelDiagramForm.handle_mouse_double_click(ModelDiagramForm* , MouseButton , Int32 , Int32 , EventState )
   위치: MySQL.Workbench.ModelDiagramFormWrapper.OnMouseDoubleClick(MouseEventArgs e, Int32 X, Int32 Y, Keys keystate, MouseButtons buttons)
   위치: MySQL.GUI.Workbench.ModelDiagramForm.CanvasPanel_MouseDoubleClick(Object sender, MouseEventArgs e)
   위치: System.Windows.Forms.Control.OnMouseDoubleClick(MouseEventArgs e)
   위치: MySQL.Utilities.WindowsCanvasViewerPanel.OnMouseDoubleClick(MouseEventArgs e)
   위치: System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   위치: System.Windows.Forms.Control.WndProc(Message& m)
   위치: System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   위치: System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   위치: System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   위치: System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

How to repeat:
I don't know. But, it happed evey time to edit my EER Diagram file.

This is a duplicate/kind of bug #66013.