This issue is similar to the one I read below but also could be different. This just started happening. The tack box randomly locked on me, but whenever the bridle rack was not above it and I replaced it, it would be fine. And whenever I would replace it with the bridle rack above it, it would not work at all. Just something I would report along with the general locking of the tack box by itself. (Very sorry I do not know the format or how to work this site.)