Final Part of 3.1

[jackslammer]

It looks like the Battle.net login server is looking at both wow.exe and launcher.exe to make sure they're both the correct version. If one of them isn't correct (like the one the Repair utility downloaded), it'll give you the unable to validate game version error. This is being looked into.

If you do not want to use a third party download for the Launcher, reverting the game will clear it up.

If anybody is still having problems with game authentication after repairing, and your launcher was reverted to the old launcher, try overwriting it with the most current one linked here

launcher.exe

it did the trick for me