Hello! I’m not sure if this is the right place to post this, but:
I’m developing a game in Unity using the Epic Online Services SDK (EOS-SDK), utilizing the Easy Anti Cheat (EAC) stuff to authenticate game clients. On a recent build, Linux players are no longer able to connect to official game servers. The game server’s logs indicate that there is an issue on the backend of EAC:
09/02/2026 03:48:05 LogEOSAntiCheat(Warning): [AntiCheatServer] Received backend info message: {“errorCode”:“errors.com.epicgames.eos.eac.deviceid_not_supported”,“errorMessage”:“DeviceID is not supported for anti-cheat since it requires a stable account identity”}
However, this player is on a Linux machine authenticating via Steam. Interestingly, the same ‘build’ works if launched on the steam account from a Windows machine. We are not using proton or anything, they are native Linux and native Windows builds.
I am NOT using DeviceIDs for Steam users at all, it’s only using Steam’s authentication (external auth). And I want to emphasize, this exact same code worked in a previous build (nothing around authentication has changed). I can even hop back in Steam builds and connect to a server and authenticate fine.
Any idea as to what could be going on here?