This has probably been running for an hour or two see attached development console file
I thought I would also add that this also happens when you have a chest on a zombie horse and a skeleton horse (I think the texture of the chest on the zombie is a planned feature 😃)
My minecraftt launcher works now I don't know if it is because of 1.3.6 or cause I left it running all night and in the morning closed and reopened it or if it's just random but it works