We have received numerous reports of players experiencing issues installing the Borderlands 2 Compatibility Pack that was released on January 14, 2013 in preparation for the Sir Hammerlock's Big Game Hunt DLC.
In most cases, the download fails to complete, and often restarts the download process as soon as it hits 99%. As a result of the issue, players are unable to play online.
We are currently investigating this issue and working with our partners to get it resolved. We appreciate your patience as we work toward a resolution.
Update 1/15/2013, 11:35 Pacific Time: This issue should now be resolved on the back-end.
Please try launching the game, and downloading the pack from the main menu.
The pack should then install without any further issues. Should you continue to have problems installing, please try the following:
1) Turn off the Xbox 360.
2) Turn the Xbox 360 back on.
3) Press the Guide button on your controller, go to Settings, and select System Settings.
4) Select Storage or Memory.
5) Select the storage device containing the Compatibility Pack.
6) Select Games and Apps, then Borderlands 2.
7) Highlight the downloaded Compatibility Pack, press A and then select Delete and hit A again.
8) Boot Borderlands 2 while connected to Xbox Live.
9) When prompted, re-download the Compatability Pack.
10) Additionally, the title update may be corrupted. Clear the system cache of your Xbox 360. This will remove all downloaded game updates, and allow you to re-download any game updates that may be corrupted. You can find instructions here: http://support.xbox.com/en-US/xbox-360/settings-and-initial-setup/c...
If you still experience the issue, please redownload the Compatibility Pack through your account history. You can find your Account History by navigating to the Settings Tab, selecting Account and Download History.
If you continue to have any issues with the compatibility pack, please feel free to open a support ticket