You're not alone, many people are complaining about this elsewhere, but I think here might be the best place. I'm having the same problem on Goblin server, disconnecting constantly every 30 seconds to 10 minutes. My ISP is green, obviously I can connect here so it's not my modem or router.

It's worth noting that it doesn't seem to be restricted by world either. People from many servers (on the NA side, anyways) are experiencing error 90000 followed closely by a brief error 3102, and occasionally followed by an error 10102. So far nobody has heard anything from the devs regarding this and it's a little disheartening honestly.