I've just installed .NET 4 on Windows SErver 2008 R2 x64 and I am getting 500 Internal Server Error with an ASP.NET MVC application which was previously running fine on 3.5. The application was upgraded from targeting 3.5 to target 4 and I personally built it today on my development machine (changed in VS - Properties to .NET Framework 4).
On the server I installed .NET Framework 4 Client profile and Full both automatically through the Web Platform Installer. ASP.NET MVC 2 was also installed through Platform Installer. I created a new .NET 4 application pool in IIS and placed the web app in it.
Also I have custom errors turned Off in web.config but even so no detailed error is displayed - just the plain IIS 7.5 500 Internal Server Error.
Any suggestions?