Bug Adding a new Script crashes Photon Namespace (VS Code)

As the title said, if I add a new script to the game, the Namespace from

Code (CSharp):

1. using Photon.Pun;

got broken, all scripts are flooded with errors - but all compiles without issues. Even the game is runing.

If I load a backup, all is runing fine, until I add another script

What can I do to avoid this issue?



I am using
Unity 2020.1.2f1 Personal
Visual Studio Code 1.46.1 (with Addon Unity Codesnippets and Unity Debugger)

 

What's the error?

 

All errors refer to the Photon scriptparts like RPC, Instantiate, ... But the script is still compiling and the game is runing. But with all those "false-errors" it is very hard to track down real errors.