I am unable to tame or ride any horses in Minecraft

When I try to tame a horse (in the new snapshot) I right click it and ride it. Normally it would either kick me off or show hearts if tamed, but instead it keeps moving forever (it does neither).

Horses that were already tamed (in my world from 1.8 that i saved, but I am playing it in the snapshot) are broken too. When I try to ride them I can not control their movement. Also when I try to jump with the horse, the horse will show the jumping animation but will not actually jump off the ground.