Cause
To prevent the spreading of viruses, malware, and spyware; prevent denial of service attacks; ensure the security of the TTUnet network; and halt illegal file sharing; Texas Tech University blocks torrents, which is what the Blizzard Downloader uses to update World of Warcraft. See Peer-to-peer software unable to connect when computer is connected to TTUnet for additional information.
Resolution
If you are experiencing problems downloading updates for World of Warcraft, try visiting a mirror site to download the updates.
OUTCOME
You can successfully download required game patches without using the Blizzard Downloader.