[2020] I am at a total lost here, Auth fail error and unique ID not valid error for near a month

Hey @mutinay

Welcome to our community.
Just to confirm, do you have any mods installed or are subscribed to any? Have you in the past?
If so, could you try to unsubscribe to all of them, delete the workshop folder and try to reproduce this problem in an official server or single player to see if it happens again? Also, did you try to validate your game files in case there any corruption in any of the files?
Thanks in advance.

Thanks for the follow-up and glad to hear your issue was solved.