If you receive an error message that reads "You are still logged into the game. Please allow a few moments for the logout process to complete." or you receive an Error [3102], and are unable to log into the game, the server may be experiencing an unusually high load.
Under these circumstances, the error may likely persist. Therefore, we kindly ask you to wait for some time before trying to log in again.
*Depending on the congestion, it may take up to several hours for the servers to recover.

If the error persists over an extended period of time, please shut down the game, restart your PC or console, and wait for a few hours before trying to log in again.

Should the issue continue to persist despite taking the steps above, please submit a bug report through the Official Forums or in-game Support Desk.

■Official FINAL FANTASY XIV Forums - In-game Bug Reports
https://forum.square-enix.com/ffxiv/forums/632

■Support Desk
Main Menu＞System＞Support Desk menu＞Contact Us＞Report a Bug