Attempt by security transparent method 'WebMatrix.WebData.PreApplicationStartCode.Start()'

For me this error was because I did NOT have Microsoft.AspNet.WebHelpers installed after updating from MVC 4 to MVC 5. It was fixed by installing the NuGet package

Install-Package -Id  Microsoft.AspNet.WebHelpers

If you are getting the error

Attempt by security transparent method ‘WebMatrix.WebData.PreApplicationStartCode.Start()’ to access security critical method ‘System.Web.WebPages.Razor.WebPageRazorHost.AddGlobalImport(System.String)’ failed.

In order to fix this install this package using NuGet package manager.

Install-Package Microsoft.AspNet.WebHelpers

After that , probably you will get another error

Cannot load WebMatrix.Data version 3.0.0.0 assembly

to fix this install this package using NuGet package manager.

Install-Package Microsoft.AspNet.WebPages.Data

For anyone landing here who is trying to upgrade from MVC 4 to MVC5, I was able to resolve this issue by following the instructions at 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 also had to install the "Microsoft.AspNet.WebApi.WebHost" package from nuget. But that's it.

Oh, and I had to create this appSetting: <add key="owin:AutomaticAppStartup" value="false" />

:)