How to fix this MVC website error: Could not load file or assembly 'System.Web.Helpers, Version=2.0.0.0

Question

I have MVC3 installed on my dedicated server and I have an mvc3 website running there, the problem is:
In some pages I get this error:
"Could not load file or assembly 'System.Web.Helpers, Version=2.0.0.0"

And I don't know what is the problem because it didn't happen before in this website or any MVC3 website on the same server.

Note: The issue is happening in some pages I am using grid helper in, but there are some other pages has grid helper and working fine.

I tried this as well: http://haacked.com/archive/2008/11/03/bin-deploy-aspnetmvc.aspx while i know it is an old post, but with no hope as well.

Answer 1

You must have installed or updated some NuGet package in your project that depends on Razor WebPages v2 (System.Web.Helpers, Version=2.0.0.0) which is part of the upcoming ASP.NET MVC 4 release.

Take a look at all the referenced assemblies and inspect their dependencies.