I have replaced this error with warring ([Fix] The C# extension is already installed #53 · JaneySprings/DotRush@be9c63f · GitHub).
… it’s still a strange scenario for me though.
This has been released and should already work somehow~.
And by the way, it only checks “ms-dotnettools.csharp”. There shouldn’t be any problems with other IDs.
As for Unity Debugger: It uses my own fork of the Mono debugger, which I created to work with MAUI (GitHub - JaneySprings/Mono.Debugger: Fork of the Mono debugger libs for .NET Meteor and DotRush). It should work pretty well with Unity. But Android/iOS debugging probably won’t work right now, but it won’t be difficult to add it, since I already have a bunch of tools for this from my old MAUI extension.