I have been having this error disconnect me since the beginning of The War Within expansion. It used to be that I would occasionally get disconnected in Dornegal, then every time I got near Mereldar. Eventually it started happening every time I log in. I found all the other forum posts with the same issue and tried all the “fixes”:
Reset UI, done several times.
Reinstalled WoW/Battlenet, done.
Swapped to wired connection, done.
Flushed DNS, done.
Spoke to my internet provider, done.
Restarted Router/Modem, done multiple times.
Bought new router/modem, done.
If it was listed on a forum as a fix, I’ve tried it. I’ve made tickets in game, I was told to re-try all the fixes that I’d already done. It used to only affect Retail, but is now affecting Cata classic. Nothing has worked, so I was told in my last ticket to try the bug report forum.