Upgraded .net version from 5 to 6 getting namespace name 'Microsoft' could not be found error

[jayhouse-github]

I have a solution consisting of the main project, a CMS website, a module and a theme. It's running on version 1.2.2 of Orchard and .Net 5 and I need to upgrade to .net 6 at least in order to then upgrade the version of Orchard Core.

The problem is as soon as I upgrade the .net version to version 6 the solution still builds but won't run. The homepage and the admin login page won't display. It looks one of the components in the view (I'm using MVC) can't find what it's looking for, the Microsoft and System namespaces. Here's the first of many errors: -

`The type or namespace name 'Microsoft' could not be found in the global namespace (are you missing an assembly reference?)

#pragma checksum "/Areas/OrchardCore.Contents/Views/Item/Display.cshtml" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "10b62daf6f27fe1c0fa7f8fe65bd34f6e838f994"
//
#pragma warning disable 1591
[assembly: global::Microsoft.AspNetCore.Razor.Hosting.RazorCompiledItemAttribute(typeof(AspNetCore._Areas_OrchardCore_Contents_Views_Item_Display), @"mvc.1.0.view", @"/Areas/OrchardCore.Contents/Views/Item/Display.cshtml")]
namespace AspNetCore
{
#line hidden
using System;
using System.Collections.Generic;
using System.Linq;`

I'm hoping the fix might be something simple but I'm totally stuck after trying for hours to fix it. Any ideas or help would be appreciated.

[weirdyang]

had the same problem, and in the end had to recreate a new .net 6 project and copy the stuff over, couldn't solve it :/

[jtkech]

After a backup, particularly the App_Data folder, try the git clean -xdf command under the solution folder.

[jayhouse-github]

Ok, thanks. I had come to the conclusion that I was going to have to do what @weirdyang has had to do but thought I'd try here first. I'll try @jtkech suggestion first then start again from a .net6 solution if that doesn't work.

[weirdyang]

thanks for the suggestion, however the issue still occurs.