Infinitely falling where there should be ground.

Put the summary of the bug you're having here

What I expected to happen was...:
I should have spawned on the ground.

What actually happened was...:
I continually fell until the game kick me off the server with a broken pipe issue. I made this crash with F3+C.

Steps to Reproduce:
I can only reproduce this on my computer every time I connect to this server specifically. It works fine on my friends laptop, but mine just does this.