Error 90001

This error has been plaguing me for weeks and I'm getting fed up with it. I've lost many HQ mats while crafting after DCing with this error and it's just flat out infuriating while playing the game. I've reset my router, ensured all cables are connected properly, added an exception to my firewall for all .exe files related to this game, all my drivers are up-to-date (even my BIOs) and even restored my computer to a prior restoration point.

IT. KEEPS. HAPPENING.

I do not understand what the hell the problem is. No other online game I play has this issue and this happens either every 5 minutes or every other hour or twice in a row. I'm at a loss. I have no idea what to do and of course, Square support is useless.

90001 versus 90002 happened to me because i set both my cellphone and the desktop to the same ip. Most people would use DHCP (auto ip) and not have this issue.

90k errors mean your connection dropped. If you're on wifi, consider a cable connection. If your router is older than 2 years, test it on another system.