Hi

Try to reinstall MVC in your solution and redeploy -

Update-Package Microsoft.AspNet.Mvc -Reinstall

Alex

thanks, I ran the command and it was successful: Successfully installed 'Microsoft.AspNet.Mvc 5.2.7'

then I published again, it didn't help, the error message stayed same

Check that you installed the asp.net MVC at least version 3 on the server

in my project, in NuGet management , the package Microsoft.AspNet.Mvc, it is version, 5.2.7.

on file system on my local, the "System.Web.Mvc.dll" has version 5.2.7-61128 same as the "System.Web.Mvc.dll" on the server

Did you install MVC on the web server?

hmmmm, I didn't, I don't know. what does it mean to install MVC on server? do I need to run some installation application? Thanks

Check all these dlls :

* Microsoft.Web.Infrastructure
* System.Web.Razor
* System.Web.WebPages.Deployment
* System.Web.WebPages.Razor

yes I have all these 4 .dll files on local and on server in \bin folder. For each file, time stamp, size, and product version are the same between my local and on server

what ASP.NET version installed on the server? Medium Trust?

ASP.NET version on server is 4.7.2, just installed last week, 2021-03-27. I am not sure how to check Trust level, but I would think it is at correct level.

AppPool is using .Net 4.0.40319, there is no option to choose 4.7.2, all my other AppPools are all on 4.0.40319 although the sites are on 4.5.

I am not sure how to check whether .Net correctly registered in IIS. This website is an existing one, it was working before on old Umbraco version, we updated it to new Umbraco 8.

in Views\web.config, I have this

<sectionGroup name="system.web.webPages.razor" type="System.Web.WebPages.Razor.Configuration.RazorWebSectionGroup, System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
  <section name="host" type="System.Web.WebPages.Razor.Configuration.HostSection, System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
  <section name="pages" type="System.Web.WebPages.Razor.Configuration.RazorPagesSection, System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
</sectionGroup>

and I have error message as I mentioned in my first post

-* - * - * - -* - * - * - -* - * - * - -* - * - * - -* - * - * -

then I added binding direct in root\web.config, see attached image

then I got different error message as :

Attempt by security transparent method 'Microsoft.Web.Helpers.PreApplicationStartCode.Start()' to access security critical method 'System.Web.WebPages.Razor.WebPageRazorHost.AddGlobalImport(System.String)' failed.

I am just running a basic Umbraco 8 site, using Visual Studio 2017, published to server from within VS.

I tried different projects, In one I made the base project with the MVC folders included, the other I didn't - they both failed the same way.

It is its own website

I didn't install other nuget packages , only the umbracocms, and I don't have build warning and error when I built it, it ran correctly on my local.

something with the server

try to reset asp net setup

I think it is server issue too, so at this point, I will put a pause on this and try different direction, thank you very much for all your help!

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