While riding a horse for a period of time (5-20 minutes) the game crashes, afterwards when you log back into the world the horse usually vanishes and you have gone back to where you were about 30-50 blocks from when you crashed. Sometimes, not always, you can find them back wherever you were minutes ago. It is very inconvenient when you are on a long adventure thousands of blocks from your base, in the middle of the night. This doesn't happen if you walk with the horses or with any other animal. I personally have experienced this several times ,or even with just riding a horse(still on the horse), and sometimes not even on it just by it and it completely disappears, and a few others I know the experienced the same issues. I wouldn't have reported this if it wasn't for the fact that It was my oldest and most important horse that vanished for good. So, I hope you can resolve this issue quickly, Thank you.