Update: the AH will be re-enabled with realm restarts in the morning.
Blizzard have been working on fixing a bug that’s not allowing players to buy anything from the Auction House. Aside from players just getting their buyout reset and getting their gold in the mail, it seems as if the sellers of the items may have lost the items entirely after the transaction stalled and just gotten their deposit back in the mail. While in the process of fixing it, they had to disable the AH while they work on the issue. Hopefully the lost items can be restored.
In order to take next steps on this issue, we’re going to disable the AH for all Cataclysm Classic realms in this region.
We’ll let you know as soon as we have further updates.