[2020] Could not connect to server: Authentication Failed

Hey @TheKatofKats

Welcome to our community.
When playing with mods, please make sure both your server and your client are running the same version of each mod and preferably, the latest possible. Make also sure you’ve set up your modlist order correctly as well. As a general troubleshooting when playing with mods, we would recommend as well visiting the official page of each mod to see if there’s other players with similar issues when playing with that mod.