When beds are placed above the 128 block height and you sleep it looks like you fall UP through the world (Y coordinate increases at a fast rate). When you leave the bed, you take a small amount of damage.
I tried it at Y=157 and I found this.
EDIT: Forgot to mention that it was on a server. I tested on vanilla client only now, and it doesn't happen. So I'll test it on a vanilla server.
CONFIRMED: Happens on a vanilla server.
ABSOLUTELY NO MODS were used in this test.
Can a Moderator move this topic to Server Support, please.
I tried it at Y=157 and I found this.
EDIT: Forgot to mention that it was on a server. I tested on vanilla client only now, and it doesn't happen. So I'll test it on a vanilla server.
CONFIRMED: Happens on a vanilla server.
ABSOLUTELY NO MODS were used in this test.
Can a Moderator move this topic to Server Support, please.
Life is a Learning Curve....
Unfortunately, you're stuck on the bottom...amongst the bones of the stupid.