c# - Could not load file or assembly 'System.Net.Http' or one of its dependencies

Question

Maybe Relevant information: I have a web application I built with .net 4.5. I wanted to deploy to Azure's Web Sites but it only supports .net 4.0 so I downgraded the project to .net 4.0. It still works when run locally.

When I publish to Azure, i get this error:

Could not load file or assembly 'System.Net.Http' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

I have tried removing the Web API with nuget and readding it, as another question on SO suggested but I still have the same problem.
I have tried close/open VS, and clean/build.

Answer 1

I solved a similar problem (System.Web.Http and System.Net.Http.Formatting) error by removing the reference to problem reference (which was pointed to my .Net installation folder) and replacing it with the reference file in my packages folder that was installed by the Microsoft.AspNet.WebApi NuGet package.