From a low angle, you can see a wall placed on the ground. This wall even has collision, you can run over the top of this wall. One side is visible, and the other isn't.
Here are some screen caps. Easiest to see in free-cam mode in-game, although you can also see it while crouching.
http://imgur.com/a/SIDkx
Should be as simple as deleting this object.
Here are some screen caps. Easiest to see in free-cam mode in-game, although you can also see it while crouching.
http://imgur.com/a/SIDkx
Should be as simple as deleting this object.