Could not load file or assembly 'System.Web.Http 4.0.0 after update from 2012 to 2013

Question

I did the upgrade according to. http://www.asp.net/mvc/tutorials/mvc-5/how-to-upgrade-an-aspnet-mvc-4-and-web-api-project-to-aspnet-mvc-5-and-web-api-2

I get the er

Answer 1

 Installing NuGet package ASP.NET.MVC solved the issue for me. 
 To install package.
 - Right click on project 
 - Select "Manage NuGet Packages"
 - Select Online->Nuget.org from left menu
 - select "Microsoft ASP.NET MVC"
 - Click Install

 If you have already installed package earlier, please update the package by selecting Updates from left menu and then selecting "Microsoft ASP.NET" and click Update.