Could not load file or assembly 'System.Web.WebPages.Razor, Version=3.0.0.0

Question

I want using external logins so I installed Oauth by package manager:

 PM> Install-Package Microsoft.AspNet.WebPages.OAuth

Then I got th

Answer 1

Apologies in advance for this lo-tech suggestion, but another option, which finally worked for me after battling NuGet for several hours, is to re-create a new empty project, Web API in my case, and just copy the guts of your old, now-broken project into the new one. Took me about 15 minutes.