Borderlands 2 players have been reporting a bug that wipes Badass rank and tokens, subsequently resetting them to zero.
That's not all, though: the challenges completed don't actually reset, which essentially means players cannot re-earn their Badass rank.
Developer Gearbox has stressed the issue is not widespread, with its technical team working on a fix.
Our engineers are looking into this, and the information you've provided has proven to be a great resource while we investigate. At the moment, it seems to be a fairly rare issue and we'll keep you updated on when we resolve it.
The PlayStation 3, Xbox 360 and PC versions of the sequel is said to be affected.