Treat Bag Will Not Open

When I right click on it, it goes gray and stays gray but doesn't actually open.

I've tried adjusting a bunch of in-game UI settings and video settings to no avail. The only way I can get it to go back to it's original state where it isn't gray is by doing a /console reloadui. Even though the bag says it will disappear when I log out, I tried that too, and while I was there, disabled the one addon I had running. I logged back in expecting it to be gone - but it was still there, with the same problem.

I have trick or treated several times already today with no issue with the bag.

Is it because it contains the last mask I need for a Mask for All Occasions :P