So it says in the Support FAQ thread:
Why am I getting a "Session Lost" when I try to join a server using the launcher?
Battleye is causing the issue so in the launcher settings, at the bottom, make sure to tick "Use Steam Protocol" and save.
But I see no such option in A3 Launcher's settings tab, or anywhere else on the launcher. Is it talking about the launcher that comes with the game? Don't see it there either. Or is this for an older version of A3 Launcher? If so, how do I stop the "Session Lost" error so I can play the game?