EntityFramework error: The provider did not return a ProviderManifest instance

Question

My project is using ASP.NET MVC4, in C# with Visual Studio 2012 for Web Express.

When compiling my project, I have the following error:

The pr

Answer 1

For me it was because when I used TeamCity to deply my site, it changed the web.config file.

It removed the connectionString and added debug=true to System.Web compilation

I manuel fixed the web.config file, and it now works for me again.