Store Robbery Issues

When hitting stores, I'll have a crowbar and my safecracking tool in my pockets. I'll enter the store, knock the shopkeeper out, and he will run away. However, upon trying to open the registers, again with a crowbar in hand, I receive a message stating "I can't open this." I've hit countless stores the exact same way, however, for some reason, this has been happening every time I hit one for the past week.

*Note - There are still stores where the shopkeeper reports that they are "out of stock" so it isn't a cooldown thing.