I managed to contact the Support Desk from in-game on a JP server, and received the following answer:
It doesn't fix anything, but it's good to at least receive some acknowledgement.
Quote:Hello and thank you for your call. We understand that you received the Error code 3102 while attempting to log in, and we apologize for any frustration it has caused. This issue has been brought to our attention and is currently being investigated further. As we continue to look into this issue, please visit http://www.finalfantasyxiv.com/ for any updated information. We thank you for your patience, and best wishes to you.
FINAL FANTASY XIV A Real Reborn team
It doesn't fix anything, but it's good to at least receive some acknowledgement.