Horses cause my world to freeze up

There seems to be an issue with the way the world loads whenever I ride a horse. 

 

As far as I know, this has only happened when I am online, but it could be happening offline as well. I simply begin riding my horse. I ride around for maybe two or three minutes, and then I hit an invisible wall. There are no objects obstructing my path, nothing that could possibly be preventing me from moving; it's as if there's legitimately an invisible wall blocking my way. To add on to this, whenever I get off the horse, I become frozen in mid-air. I end up having to restart the world every single time it happens. I'd like this bug to be addressed as soon as possible, because I have a large world and traveling by horse is a necessity. Thanks!