Issue in Global.asax.cs page in MVC4

Make sure you have assembly System.Web.Http.WebHost.dll referenced. This is where GlobalConfiguration is.

With .NET Framework 4.5.1, GlobalConfiguration is found in System.Web.Http:

PM> Install-Package Microsoft.AspNet.WebApi.WebHost

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.