Question Switched windows user, now my project is broken

I got multiple users in windows and i naively wanted to look something up in Unity on user A while usually using user B for working with unity. Didnt work on User A, all project files "incompatible", went back to user B where it worked before. Now also broken.

This is what it looks like

• Unity 2020.1.11f1
  
• Microsoft Visual Studio Professional 2019, Version 16.8.3
• Visual Studio 2019 Tools for Unity 4.8.2.0 up and running
• Just this one project, others still work.

What i tried to fix it;

• kill all temp files, lib files, solution files etc. in the project folder. According to git, there's nothing different from the version that worked fine yesterday
• kill all appdata/local etc. unity temp files
  
• googled it, made sure to check if addon is active etc.

 

I solved it doing the stuff i already did multiple times and i still have no idea why it didnt work and what exactly helped.