Razor Host Factory error

I resolved this issue by setting System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc Version to 5.2.0.0 and it worked, finally! Why 5.2.0.0? Same version as NuGet Microsoft ASP.NET project.

So, the line in /Views/Web.Config should be:

<host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, Version=5.2.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />

For the benefit of anyone developing ASP.NET MVC 5 web apps using Xamarin Studio v5.5.3 on OSX, deleting the /Views/Web.config did not work for me and created other errors.

To fix it, open /Views/Web.config and change all instances of 5.2.0.0 to 5.2.2.0

More details here