Attempt by method 'System.Web.Helpers.Json..cctor()' to access method 'System.Web.Helpers.Json.CreateSerializer()' failed

I forgot about this question and I found my answer in the meantime. I think it was somewhere on Microsoft's Connect site but I am not sure. So let's share it now.

Basically, in order to workaround this problem you need to make sure "Enable the Visual Studio hosting process" is unchecked in your project's settings under Debug. I am not sure why it's happening but this is definitely a way to "fix" it. I stopped searching for answers once I found out about this. It was good enough for me.