Don't know how to use latest tools at all, please give help!

When I try to build my Content using MGCB, it creates these new .mgcontent files but the framework is still expecting .xnb files… which are not generated. Why are my .xnb files not being generated when I run the command mgcb /b .\Content\Content.mgcb? This is a DesktopGL project and I just updated the frameworks today. The project builds but I can’t continue without my shaders and fonts being built, please help!

dotnet mgcb-editor gives the following error:
Specify which project file to use because this 'I:\dev\BlugenUpdate\Blugen' contains more than one project file.

There’s only one .sln and one .csproj, what do I do?

This should help
MonoGame, meet VSCode - DarkGenesis - indie development for the new world order (