Players on both the Xbox 360 and PC platforms (PS3 appears to not be available for download yet) are reporting bug issues with the latest patch and download necessary to play as Borderlands 2's latest character, Gaige.
According to threads on both the official Gearbox forums and Giant Bomb's, some players are experiencing a loss of their Badass rank, which was actually a problem players had even before this update. Whether this is a return of the bug, or simply previously unaffected players experiencing the bug for the first time isn't clear.
Others are reporting more extensive issues, like the loss of character skins, golden keys and full saves.
We've tried replicating the problem on our end on the Xbox 360, but everything appears in order. Let us know if you have problems in the discussions below, and maybe hold off on downloading the patch and Mechromancer until this clears up.
Update: Mike Fahey says his progress on the PC version seems just fine too.
We've reached out to 2K on the matter and will update if we hear back.