[2020] Pak file corrupt or tampered with. Have done a clean reinstall and verified integrity of game files through Steam. Still not able to log into ANY server

Hey @Heresiarch

Welcome to our community and apologies for the frustration.
It seems you’re playing on a private server. Do you have any mods installed?
If so, could you try as a troubleshooting tip, to uninstall them and delete the mod folder and mod list file (you can back them somewhere else in your computer), check for integrity of the game and see if this issue happens with the unmodded version of the game?