[2021] access error to game data

Please Add CK3.exe to the exceptions list of your antivirus app; ESPECIALLY if you have Windows Defender, add it to the Ransomware "Apps Allowed Through" list.

You should add steam.exe and C:/users//AppData/Local/Programs/Paradox Interactive/launcher-v2.2021.9/paradox launcher.exe to that list.

All the best!  

Disabling AV apps does not shut them down completely. Which one do you use?

You added all three of those .exe files to all its exceptions lists?  

That's because they all use the same installation of the same launcher.

Can i please see a screenshot of the Ransomware screen where you've put in those exemptions? Thanks!  

That's not the Ransomware screen, that's the firewall - a completely unrelated function. Firewalls only govern external communications, they have nothing to do with file system access.

In the Windows search box enter Ransomware. Enable Controlled Folder access if disabled, then go into the Apps Allowed Through section. THAT is where those three .exe files need to be added as exceptions.

Good luck with that!