I was getting this strange error opening up a website solution in Visual Studio 2012.
Reference.svcmap: Could not load file or assembly 'System.Web.Mvc, Version=188.8.131.52, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified. App_WebReferences/WebServiceName/
Turns out I’m not alone, there are a number of people suffering from this problem.
I think the best solution is on Chris Towles blog, just adjust your Service Reference Settings to disable “Reuse types in references assemblies”. Problem solved. 😉