To fix the error, you must ensure your server configuration allows loopback IP addresses, that the Headless Client (HC) bypasses or signs the BattlEye license check, and that all game modifications match precisely between the server and the client. This issue occurs when Steam or BattlEye treats the automated headless process as an unauthorized player connection, kicking it immediately upon join. Why Headless Clients Fail Steam Authentication
: Open the HC’s profile file ( .Arma3Profile ) and add or change the following line: battleyeLicense = 1; arma 3 headless client steam authentication failed hot
Think of your server as a guarded club. If the HC isn't on the guest list, Steam's "bouncer" will kick it out immediately. To fix the error, you must ensure your
Sometimes, BattlEye misidentifies the Headless Client's automated traffic as a bot. Check your battleye.cfg and ensure it is not set to block the HC's IP range. You can test this by temporarily disabling BattlEye ( BattlEye = 0; in the config) to see if the HC connects. If it connects without BE, you know your BE filtering is the issue. If the HC isn't on the guest list,
Running HC as a different user or under system services
If you've been running the server for a while, Steam's authentication session might have timed out or "gone cold".