Learn more about this change here.
For help regarding Aternos, we recommend you to visit our support center.
Yayyy! 
Display MoreDear Aternos Community,
we´re proud to announce that users are now able to create a snapshot server.
The snapshot-versions will be automatically updated within 10 minutes after mojang´s release.
We hope you enjoy th update, if you have suggestions create a thread in our forums!
Nice 
Ehh... there is something wrong with the snapshots? Please fix it!
I got a world with the newest snapshot and i cant start my server. if i start it with another version it will delete some items :P?
I dont want to lose my world!
Huh? You said i should reinstall my server.. if i do that i will delete ANYTHING. Your comment does not make sense?
THANKS!!!
It's working now.. i think ._.
I need to wait 20 min (queue), i will reply back 
SnapShots?
I dont get it
Basically the snapshots (aka 1.12 features released for testing) can be accessed through Aternos so you can play with the parrots with your friends!
