Quote Originally Posted by SanjiroLionheart View Post
I've gotten the same issue twice today, scared the hell out of me....for it to say AUTHENTICATION FAILED...I thought I was hacked lmao. Software Token user myself, but still gave me a fright.
Got me a fright as well, but for different reasons

Quote Originally Posted by Nanga View Post
Here is my theory: Perhaps it does have something to do with the server transfers. Perhaps something with checking for existing character names on that server, and causing someone with the same name to get disconnected.
Unlikely, all characters with my name belong to me; one on Hyperion, one on Ragnarok.

Quote Originally Posted by Abelli View Post
I've been asking people I've seen d/c and from what I can guess it happens about 3.5hours after you log in. Having people log out and back in before instances may not be such a bad idea. Or before crafting.
I can confirm the timespan, it's about 4 hours.

Quote Originally Posted by MeowyWowie View Post
I wouldn't worry too much about it. Even though it sucks to have to log back in, I'm pretty sure it's just your session ID expiring (which is a good thing) except it kicks you off when it expires. Probably just something they did temporarily to curb account hackings.
That's how it looks to me as well

Quote Originally Posted by TehfTsala View Post
Yep had it myself twice


[EU] Issue With Account Authentication Error Message (Oct. 16)

Since the 2.05 Hot Fixes patch implemented on Oct. 15, 2013, we have confirmed an issue in which, during gameplay, players may see the “90000 Error” or “Square Enix Account Authentication Error” message displayed, and be disconnected from the server.

Investigation is currently underway, and we anticipate the implementation of a fix in the very near future. We apologise for any inconvenience and thank for your patience and understanding.
Well, at least they're working on it™

Additionally, since the “Square Enix Account Authentication Error” message is one that is displayed when an account’s contract period has expired, if your account contract period has not yet expired it will be possible for you to log in again once you restart the game.
I always wondered, do they have a number limit or why can't they have a separate "Your subscription period has ended" error message?