I had this server with my friends a while back, and when trying to log in again, for nostalgia, we realized that our world was not there.
Did Aternos remove old maps that didn't have any activity? 
Any help appreciated thank you
Posts by Martimzao
The Aternos forums are now deprecated
Learn more about this change here.
For help regarding Aternos, we recommend you to visit our support center.