Leaving and re-entering a save while on a horse causes the horse to vanish and the player to fall down from where they were while riding the horse
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Leaving and re-entering a save while on a horse causes the horse to vanish and the player to fall down from where they were while riding the horse
migrated
(Unassigned)
Unconfirmed
Minecraft 14w19a
Retrieved
I have also had this happen.