Square Enix has confirmed that it's aware of an error causing the Final Fantasy XIV Steam version to crash. Unfortunately, the studio doesn't yet know what's causing the error, as the problem doesn't appear to be happening to every Steam player.
What Final Fantasy XIV Steam error are people experiencing?
Currently riding a wave of popularity thanks to the release of latest expansion Endwalker, Final Fantasy XIV on PC is available on both Steam and via its own client, but Steam players are now reporting a pretty serious error. Since the implementation of Patch 6.08 hotfixes today, players have been complaining of a bug that stops Final Fantasy XIV from starting up on Steam. The bug simply displays a message stating that the game has been "unable to retrieve the necessary information" from Steam, and that players should reboot the game from the Steam client. Of course, doing so doesn't fix the problem.
On the Final Fantasy XIV subreddit, players are theorizing that the error is being caused by trying to play the game without launching Steam first. You can still fire up Steam, launch Final Fantasy XIV, then close Steam, apparently, but attempting to play the game without Steam open could result in this error message. However, Square Enix says it's "currently investigating" the issue, so there could be more to the error than this. The studio does say that players should launch the game through Steam since it linked Square Enix accounts with Final Fantasy XIV on Valve's platform, though.
How can you fix this Final Fantasy XIV Steam error?
If you want to fix this error, first try launching the game through Steam rather than firing it up via its own executable. After the game has launched and you're safely exploring Eorzea, you can then close down Steam if you want, but it seems you need the Steam client open to play the game now. Of course, since Square Enix says there seem to be cases in which the game has "been launched and played without any problems", there's a good chance other things could be causing this error. It's definitely worth trying to play through Steam first to see if that fixes your issue, though. If you're still experiencing the problem after trying this step, head to the Square Enix Support Center for further steps.
It's in Square Enix's best interests to fix this issue as soon as possible. After Endwalker caused lengthy login queues due to its unexpected popularity, Final Fantasy XIV is riding high, but if players continue to experience this error, it could turn some away from the game ahead of the launch of Patch 6.1 next month. You can grab Final Fantasy XIV on PC and PlayStation platforms right now.