Hey all, I'm kind of at my wit's end here, so any help would be much appreciated.

I've played on Icecrown with no issues for a long time now. I wanted to try out MoP, so I installed the Mac installer here: http://forum.warmane.com/showthread.php?t=320450

I didn't change anything to any of my WOTLK files. I didn't overwrite any of my WOTLK files. I genuinely do not understand why or how installing MoP could have affected WOTLK, but it certainly did. I am unable to log in to Icecrown or Frostwolf. I can launch both game clients with no issue, but after entering my username and password, I recieve a "the information you have entered is not valid" error, eventually followed by a "Cannot log in to World of Warcraft at this time. Please try again later." error after a few attempts. I am obviously entering the same information that I have since I started playing. I tried disabling 2FA, as well.

I have tried clearing my cache, re-installing the data files for MoP, and changing the realmlist file (for WOTLK) and the config file (for MoP) to have just "set realmlist logon.warmane.com" and nothing else. I am getting nowhere.

I'm wondering if the issue is related to language packs? The MoP client came with enGB, while I usually use enUS. I tried matching the two clients to no avail. I really don't know, but now I feel like an ***** because I can't log in to either servers. I am running OS X El Capitan 10.11.16.