It could be that one of the retaining springs came unseated. This happened to me once when I redid my parking brake shoes and assorted hardware, I hadn't properly situated one of the springs, it popped out, and needless to say there was a fair amount of grinding and scraping going on. Luckily, no further damage. S-o-o, purchase of another hardware kit (price wasn't that bad, if I recall, from BavAuto), and this time I made sure everything was put back exactly where it should be.
Assuming that this is the problem, it's probably worthwhile replacing all that hardware anyway, in my case the sprockets were so corroded and arthritic they could barely rotate, so adjustment was additionally frustrating. Good luck.