Cant open bags.

[Meta-Shadow]

With all of my characters, I cant seem to open any of my bags. I downloaded a new UI from this site and a friend of mine got the same one. I was playing on his computer the other day and on his, I could open my bags normally. But like I said, I cant open any of them on my computer.
If you have any idea on what the problem could be, I would most like to hear it.