Error 3101 is keeping me out of the game. I just came back after a year.

[Sirmarki]

I managed to log in on a friend's machine, and my characters were there, and I got to properly log in... Could the issue be with my PC or my ISP's hardware?

Have you tried logging in again on your current setup?

You could try reinstalling your network drivers and any USB networking/wifi devices?

But it could well be an ISP issue.