Hi All,

I'm having the same issue as this thread. However, between my two versions the umbracoSettings file is identical.

For those who don't want to read the linked thread the error message I'm getting is this:

System.InvalidCastException: [A]System.Web.WebPages.Razor.Configuration.HostSection cannot be cast to [B]System.Web.WebPages.Razor.Configuration.HostSection. Type A originates from 'System.Web.WebPages.Razor, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' in the context 'Default' at location 'C:\Windows\Microsoft.Net\assembly\GACMSIL\System.Web.WebPages.Razor\v4.02.0.0.0_31bf3856ad364e35\System.Web.WebPages.Razor.dll'. Type B originates from 'System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' in the context 'Default' at location 'C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\root\c1678bbb\3c8fa7e6\assembly\dl3\ef58b4f6\e15acbe9f34ed101\System.Web.WebPages.Razor.dll'. at System.Web.WebPages.Razor.WebRazorHostFactory.GetRazorSection(String virtualPath) at System.Web.WebPages.Razor.WebRazorHostFactory.CreateHostFromConfig(String virtualPath, String physicalPath) at System.Web.WebPages.Razor.WebRazorHostFactory.CreateHostFromConfig(String virtualPath) at System.Web.WebPages.Razor.RazorBuildProvider.GetHostFromConfig() at System.Web.WebPages.Razor.RazorBuildProvider.CreateHost() at System.Web.WebPages.Razor.RazorBuildProvider.getHost() at System.Web.WebPages.Razor.RazorBuildProvider.EnsureGeneratedCode() at System.Web.WebPages.Razor.RazorBuildProvider.getCodeCompilerType() at System.Web.Compilation.BuildProvider.GetCompilerTypeFromBuildProvider(BuildProvider buildProvider) at System.Web.Compilation.BuildProvidersCompiler.ProcessBuildProviders() at System.Web.Compilation.BuildProvidersCompiler.PerformBuild() at System.Web.Compilation.BuildManager.CompileWebFile(VirtualPath virtualPath) at System.Web.Compilation.BuildManager.GetVPathBuildResultInternal(VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean throwIfNotFound, Boolean ensureIsUpToDate) at System.Web.Compilation.BuildManager.GetVPathBuildResultWithNoAssert(HttpContext context, VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean throwIfNotFound, Boolean ensureIsUpToDate) at System.Web.Compilation.BuildManager.GetVirtualPathObjectFactory(VirtualPath virtualPath, HttpContext context, Boolean allowCrossApp, Boolean throwIfNotFound) at System.Web.Compilation.BuildManager.GetCompiledType(VirtualPath virtualPath) at System.Web.Compilation.BuildManager.GetCompiledType(String virtualPath) at System.Web.Mvc.BuildManagerWrapper.System.Web.Mvc.IBuildManager.GetCompiledType(String virtualPath) at System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer) at Umbraco.Core.Profiling.ProfilingView.Render(ViewContext viewContext, TextWriter writer) at System.Web.Mvc.HtmlHelper.RenderPartialInternal(String partialViewName, ViewDataDictionary viewData, Object model, TextWriter writer, ViewEngineCollection viewEngineCollection) at System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData) at System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model) at ASP.PageViewsPartialsgrideditorsbase_cshtml.Execute() in {path to code}\Site\Views\Partials\Grid\Editors\Base.cshtml:line 20

This error is ONLY happening for custom grid editors all other razor views are working correctly (or at least seem to be). I've tried advise from this Stack overflow error as well

Nothing so far has helped. I've tried completely re-creating the view and I've tried creating a basic view that simply has a span with some text in it. The latter allowed it to render in the back end but it still fails in the front end.

Any help would be appreciated and is quite urgent.

Nik