I been reading 3100 square says its client side.
set my computer to update overnight when i woke up this morning check to see if it was finished and it was. try to log in and bingo Error 3100.
im not running a personal firewall unless its a default windows setting.

most post on the internet about this problem are a dead end.
so im asking anything new regarding this?

seeing in how im at work now i wont get to try to fix it till i get home.
when i do ill look up what ports ffxi needs and play with my wifi router.
the router more then likely has a firewall and needs adjusting.

but i would like to minimize troubleshooting time.

any help?