Well they didnt fix the server 90000 problem yet lol
This problem may not be SE problem... It is a disconnect issue.. I had it for a while and it turned out to be my wireless... Changed to hardwired and no issue ever with it again.
Another friend had it but his isp is terrible. He took his laptop over by me and had no issues at all.
It's definitely an SE problem. Had a character plagued by the 90000 error... couldnt advance passed a certain point in the questline w/o getting DCd every single attempt. My main sat at 15 w/o getting access to the airships.
I gave up and started a new character on a JPN server and leveled a diff class to 16, got airship pass, leveled another class, and fishing and never got that error once. It's most definitely an error with the instanced servers for North America.