http://support.na.square-enix.com/fa...b9o1qodmpavb90

these are the ports u need to open on your router! this is kind of advanced computering, so u might need someone to help you.
I was getting 90000 all day until i opened these ports on my router, since then, not a single 90000 error and no more lag either. Windows Firewall already has these ports opened, but there is a good chance your router doesnt. anyway, it worked for me!