https://plutonium.pw/docs/server/t5/setting-up-a-server/

Where is the config file located? I can try to delete it and see if I can play the game normally

First, make sure to update Plutonium: https://plutonium.pw/docs/update/#how-to-update-plutonium-mod
Second, if Plutonium is updated but you’re still facing the error, then the cause of the error is joining a server that’s running a DLC map which you don’t have installed. If you own the DLCs, search your Steam library for “Black Ops”, you should find 2 apps for BO1. Then, right-click the Multiplayer app, select Properties… > DLC, then mark the DLCs as checked.
EC4E254F-0FDD-41CE-9AC0-0D57FDBD9C98.png

Found a fix?

Did u find any solution? something similar happened to me

DMac_442 loool, you startred recording in the moment i got glitched lmao

Tried that but still dosnt work for me

epvitaxddd Use Steam to change the language, other methods are unsupported.

What you said?

Deleting the game and plutonium and reinstalling would be the first thing to try

Other free alternative?

Please, search for this error message. You will find many threads that cover the same issue which have already many replies.
You CANNOT do anything, the server needs to be restarted. Join another server.

Sandro_XD_03 You will not receive any kind of support. Use the steam version.