I my ASP.NET MVC 4 Project, my Global.asax.cs
page shows the error on
WebApiConfig.Register(GlobalConfiguration.Configuration);
Update-Package Microsoft.AspNet.WebApi.WebHost -reinstall
This worked for me. I was facing issues with the reference not being updated correctly on Update-package or even removing and installing the package again.
The above command reinstalls all dependencies, and usually does the trick whenever I face nuget package reference issue.