Update 13 August 2025: The developers finally released Linux binaries for Aquatica. Other issues, such as with mods, remain.
The ARK: Survival Evolved developers released the Aquatica DLC on 16 July 2025.
They broke it.
No server files were released at all for Linux.
Server files were released for Windows, but had many issues, including not working with any mods.
The developers are continuing to work on fixing the issues, but it is slow-going. You can follow their progress on their discord.
In the meantime, they released a “preaquatica” branch, allowing the game and server to be run in the same way as before the Aquatica DLC release.
You can enable this branch in AMP under Configuration > Updates > Steam Downloads > Server Branch.
If you don’t see this setting or the Pre-Aquatica option in your ARK: Survival Evolved instance, update the instance from the main instances page in AMP (click on the down arrow on the instance tile).