[2022] Cant install mods why?

That looks like a file system access issue. Are you seeing any other errors in the launcher, whether related to mods or not?

Has this always happened for you or it used to work?

What launcher version do you see? Current is 2022.1

And what antivirus app do you have?  

That is usually an antivirus app getting in the way. You need to make sure all these apps are in its exceptions lists:

ck3.exe (in the Steam CK3-binaries folder)
dowser.exe (in the Steam CK3-launcher folder)
C:/users//AppData/Local/Programs/Paradox Interactive/launcher-v2.2022.1/paradox launcher.exe
C:/users//AppData/Local/Programs/Paradox Interactive/bootstrapper-v2.exe

Good luck with that!