I believe this is one of the more critical bugs on the map.

A user on reddit submitted this video showing two players getting permanently stuck: http://www.twitch.tv/pwnster1357/c/6759095

I recorded a demo on my private server of it happening with my friend, but the demo's legitimately broken. When we got stuck and I went to stop the demo, I noticed my console was flooded with a "too many stacking levels" error:
http://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=451340154

How we reproduced it: Both my friend and I held crouch and spammed jump; it seems to be most reproducible on the left side of the boost (above the garbage bags but within the hole) against the wall. Once it occurs, the bottom player is clipped (or genuinely stuck, I'm not sure) into the dumpster, and the top player floats freely in the hole.

What I've noticed is that the top player is constantly moving forward; even of they do an instant 180 they'll float across the middle of the opening without being able to jump & free themself.