Fix for Expression Blend 4 crashing on startup

If you are among the many .NET developers who have recently installed Visual Studio 11 Developer Preview and are installing the recently released Windows Phone SDK 7.1 (Mango) RTW, you may find that Expression Blend 4 is crashing when you attempt to run it.  In fact, if you debug it you'll find you are getting a System.ExecutionEngineException.  This is due to an issue in the .NET 4.5 version that was installed as part of VS11.  To get Blend back up and running you'll need to run the following commands from the Command Prompt:

 %windir%\Microsoft.NET\Framework\v4.0.30319\ngen uninstall "%ProgramFiles(x86)%\Microsoft Expression\Blend 4\Microsoft.Expression.Framework.dll"
 %windir%\Microsoft.NET\Framework\v4.0.30319\ngen uninstall "%ProgramFiles(x86)%\Microsoft Expression\Blend 4\Microsoft.Expression.Blend.dll"
 %windir%\Microsoft.NET\Framework\v4.0.30319\ngen uninstall "%ProgramFiles(x86)%\Microsoft Expression\Blend 4\Microsoft.Expression.Project.dll"
 %windir%\Microsoft.NET\Framework\v4.0.30319\ngen uninstall "%ProgramFiles(x86)%\Microsoft Expression\Blend 4\Microsoft.Expression.WindowsPhone.dll"

Happy Blending!