A Random Disconnection has Occured

I get this every now and then. I'm playing, then it syncs out and I go back to the login screen. All I see on the bottom left is the message "A Random Disconnection has occurred.". Something like that.

I just lost a 48 ranger because of that about 3 minutes ago. Took the waypoint, roamed for about 10s and then dc/ed. When I log back, it's on default league.

I mean, why does this happen? I don't seem to have issues with disconnects playing any other games. And this just made playing hardcore a pain in the neck.

Does anyone have a fix for it? I don't think I'll be playing until I know how to fix it. It's just depressing to lose chars to that :/

(Oh, btw, I'm not exactly sure if I posted this on the right section... so if I didn't, can some mod please move me? Thanks in advance)

And I'm not trying to restore my character. I just want to make sure this doesn't happen in the future. Or at least with a lesser frequency.