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

Another option is to update the Microsoft.AspnNet.Mvc NuGet package. Be careful, because NuGet update does not update the Web.Config. You should update all previous version numbers to updated number. For example if you update from asp.net MVC 4.0.0.0 to 5.0.0.0, then this should be replaced in the Web.Config: