Razor Host Factory error

Question

I get a MvcWebRazorHostFactory error trying to run my app, but it's not an MVC app at all. I have the following web packages installed via nuget:

Microsoft ASP.NET Razor Microsoft ASP.NET Web API 2.1 Microsoft ASP.NET Web Pages 

My app is angularjs front end using razor views (.cshtml). I don't understand why I keep getting this error.

An exception of type 'System.InvalidOperationException' occurred in System.Web.WebPages.Razor.dll but was not handled in user code  Additional information: Could not locate Razor Host Factory type: System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35 

And here is the razor section in my web.config:

<system.web.webPages.razor> <host factoryType="System.Web.WebPages.Razor.WebRazorHostFactory, System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" /> <pages pageBaseType="System.Web.WebPages.WebPage">   <namespaces>     <add namespace="System.Web.Configuration" />     <add namespace="System.Web.Optimization" />     <add namespace="System.Web.Routing" />   </namespaces> </pages> 

Answer 1

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" /> 

Answer 2

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