I had the bright idea of updating my perfectly working ASP.Net MVC 4 application to the MVC 5 via nuget, Everything compiles just fine but when I try to run the application I get the following yellow screen of death. Has anyone gotten this or know how to solve it? I've searched for it and couldn't find any solutions. Please let me know if there is any farther information that would help you that I can give you. Attempt by security transparent method 'WebMatrix.WebData.PreApplicationStartCode.Start()' to access security critical method 'System.Web.WebPages.Razor.WebPageRazorHost.AddGlobalImport(System.String)' failed. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.MethodAccessException: Attempt by security transparent method 'WebMatrix.WebData.PreApplicationStartCode.Start()' to access security critical method 'System.Web.WebPages.Razor.WebPageRazorHost.AddGlobalImport(System.String)' failed. Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. Stack Trace: [MethodAccessException: Attempt by security transparent method 'WebMatrix.WebData.PreApplicationStartCode.Start()' to access security critical method 'System.Web.WebPages.Razor.WebPageRazorHost.AddGlobalImport(System.String)' failed.] WebMatrix.WebData.PreApplicationStartCode.Start() +112 [InvalidOperationException: The pre-application start initialization method Start on type WebMatrix.WebData.PreApplicationStartCode threw an exception with the following error message: Attempt by security transparent method 'WebMatrix.WebData.PreApplicationStartCode.Start()' to access security critical method 'System.Web.WebPages.Razor.WebPageRazorHost.AddGlobalImport(System.String)' failed..] System.Web.Compilation.BuildManager.InvokePreStartInitMethodsCore(ICollection`1 methods, Func`1 setHostingEnvironmentCultures) +556 System.Web.Compilation.BuildManager.InvokePreStartInitMethods(ICollection`1 methods) +132 System.Web.Compilation.BuildManager.CallPreStartInitMethods(String preStartInitListPath, Boolean& isRefAssemblyLoaded) +102 System.Web.Compilation.BuildManager.ExecutePreAppStart() +153 System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException) +516 [HttpException (0x80004005): The pre-application start initialization method Start on type WebMatrix.WebData.PreApplicationStartCode threw an exception with the following error message: Attempt by security transparent method 'WebMatrix.WebData.PreApplicationStartCode.Start()' to access security critical method 'System.Web.WebPages.Razor.WebPageRazorHost.AddGlobalImport(System.String)' failed..] System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +9885060 System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +101 System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +254