Good afternoon, I saved a world with a mod that I didn't explore it, so I uninstalled it because I saw that I wasn't getting a good game performance. Now it's saying that the server needs this mod to work, but if I install it I can't play on the server. What to do to solve this problem? 
Posts by Susno_
The Aternos forums are now deprecated
Learn more about this change here.
For help regarding Aternos, we recommend you to visit our support center.