Since logging in I've disconnected more than a handful of times (over an 80 minute playtime) then received the above mentioned Error Codes.

Steps taken to "solve" issue:
--close program, start again
--restart computer
--check for updates/drivers
--reset modem
--speedtest to ensure adequate internet (Cable, 40+Mbps result)

Lag and disconnection occurs regardless of character, job, or zone. All on Famfrit server whether as SMN, FSH, BRD, despite task (handing in quests, in combat, fishing, attempting to use summoning bell.)

I disconnect and am given the 900000 error followed by 3102 stating character still in game. Closing FFXIV ARR and restarting I received a windows pop up with the Error Codes 30410, 30607, 20459, 10009, 10019....twice.