I’m running macOS Sonoma using VS Code
And when I select opening content.mgcb with the editor I get this in Output
Users/<name>/Desktop/code/games/monogame/MyGame/MyGame.csproj : warning NU1803: You are running the 'restore' operation with an 'HTTP' source, 'http://teamcity.monogame.net/guestAuth/app/nuget/feed/_Root/default/v3/index.json'. Non-HTTPS access will be removed in a future version. Consider migrating to an 'HTTPS' source. [/Users/<name>/Desktop/code/games/monogame/MyGame/MyGame.sln]
/usr/local/share/dotnet/sdk/8.0.100/NuGet.targets(156,5): error : Unable to load the service index for source http://teamcity.monogame.net/guestAuth/app/nuget/feed/_Root/default/v3/index.json. [/Users/<name>/Desktop/code/games/monogame/MyGame/MyGame.sln]
/usr/local/share/dotnet/sdk/8.0.100/NuGet.targets(156,5): error : Network is unreachable (teamcity.monogame.net:80) [/Users/<name>/Desktop/code/games/monogame/MyGame/MyGame.sln]
/usr/local/share/dotnet/sdk/8.0.100/NuGet.targets(156,5): error : Network is unreachable [/Users/<name>/Desktop/code/games/monogame/MyGame/MyGame.sln]
The editor looks weird and if I right click on the Project window the editor just closes

And this is in the Problems log
And I don't know if it's related but when I run
dotnet new --install MonoGame.Templates.CSharp
I get this error
MonoGame.Templates.CSharp (version 3.8.1.303) is already installed, it will be replaced with latest version.
MonoGame.Templates.CSharp::3.8.1.303 was successfully uninstalled.
Warning: The NuGet sources http://teamcity.monogame.net/guestAuth/app/nuget/feed/_Root/default/v3/index.json are insecure and will not be searched. If you want to include those sources for search, use --force.
Error: Failed to load template from /Users/<name>/.templateengine/packages/MonoGame.Templates.CSharp.3.8.1.303.nupkg(/content/content/MonoGame.Application.UWP.CoreApp.CSharp/.template.config/template.json).
Details: 'identity' is missing or is an empty string.
Success: MonoGame.Templates.CSharp::3.8.1.303 installed the following templates:
