Nostalrius Begins - Quality wow vanilla realm (1.12)

Account creation does not appear to be working at the moment. The process appears to complete successfully, but if you try to log into the forums you receive an "Incorrect username" error. In game, the error returned after authorization is "Unable to Connect." This is the case even after verifying the account via email.

I suspect this may be the problem for others who still can't connect. Account creation appears to work, but is not actually syncing to the game and forums.

Is this a known issue, or is there any known fix?

I'm experiencing the same problem. It's a real pain in the proverbial and seems to be the only thing stopping me from logging in to the game itself.

Forum uses different registration than game account I believe.

Anyway, I think I found a solution.
Go create a new account where your password is between 8 and 16 characters long + it must contain one number. Shorter passwords and passwords without a number won't let you log in and return the unable to connect error.
That helped me.

Did nothing for me. Getting desperate now.