IIS 7.5, ASP.NET MVC. HTTP Error 500 (Internal Server Error): An unexpected condition was encountered while the server was attempting to fulfil

Question

I have a MVC3 web site, which works well on IIS Express, but after publishing to IIS 7.5 I got that weird error. The full error message is:

HTTP Error 500 (Internal Server Error): An unexpected condition was encountered while the server was attempting to fulfill the request.

I published using 'File system' method, for web site I created a separate site in IIS, separate application pool with .NET 4.0 and Integrated mode.

Can you help me diagnose that problem?

Solution

I assume you're using Chrome as your web browser? This is the default error page Chrome displays when it receives a 500 HTTP response from the server with no content.

You need to find the cause of this error. Open the Event Viewer (Win+R, type "eventvwr.msc", click OK). Expand "Windows Logs" and click "Application". Look for an error or warning that relates to IIS, W3SVC or similar. It's likely an error that's occurring before the request reaches the .NET pipeline.