It seems that some players of Borderlands 2 have lamented the cancellation of special tokens, Token Badass linked to Hard Level, conquistabili by completing challenges and that allow us to get special items during the adventure. The bug as well as erase all the conquered token also eliminates the prizes unlocked. In a press release, Gearbox claims to be already working to eliminate the problem seems to be caused by some corrupt save file.

Below is a video showing us the glitch in question: