It most likely means you're not on the right patch (for me, 4.3.4), or don't have the right realmlist set. Try opening your -retail- WoW launcher and updating to the latest patch. After done, close the launcher, and run repair. After that is finished, go to your main WoW directory, then to the "data" folder, than to your local folder, (either enUS or enGB, depending on where you live), and locate your "realmlist.wtf" folder. Open it, and erase everything inside, and replace it with...
SET realmlist login.icecold-wow.com
After done, go to File>Save, then exit. Open up your Icecold-WoW launcher again, and click on "delete patches", then "Player Reaper". Hope this help!
Yours truly,
Zurlock.