I just came back to wow after a 6 month break. I don't remember my product key, and when i go to Log On - Buddy Auth Portal to see it, it says my account info is invalid. I used the same log in info I used to access these forums and I even reset my password to just see if it would help.
auth portal info is not the same as the forums info are you registered with the same email u used in checkout page?
