I had the same problem. her is what helped me. I took off the button lock stops that slide on the string, on the side of the camera that opens, and just tied them to the holes. then on the hinge side after wrapping around the tree, put the strings thru the front of the holes instead of from the rear, so your button lock will be on the back side of the holes and not in the way on the front side of them. hope you can make sence of this.
Dan