No idea what Happen, I was Just adding "//" notes to my script and this popped up. and now my script doesnt work properly!
This isn't a thread for Visual Basic help, and even if it were, we' would have needed to see the code you were editing to even hope to help you.
From the namespace 'Microsoft.CodeAnalysis,' it looks like another bug in Visual Studio. That said, if your script was working and stopped working, then you must have introduced a bug somewhere. What Visual Studio thinks of your code is actually irrelevant, since it is Unity that ultimately compiles it for running. Try selecting any script in your project and right-click-reimport that script, then see if there are any errors in the Unity console window. That's what actually counts.