[Hable]

http://imgur.com/Pb3s3sC
Very weird experience,happened a while back,but I still want to know why the hell this happened lol.

[povargek]

You don't change a gravity?

[AaronFarley]

usually happens when you teleport way outside the world boundaries, you dont specify a player class on spawn/join or you set the gravity way too high. may be more but thats what i know.