Singleplayer LAN World: Second player not able to move when joining

What I expected to happen was: that I would be able to load in with my friend and go ahead and play.

What actually happened was: that the world didn't load. I could see the moon in the sky and the sun below me. I could turn in a circle, and switch items in the hot bar, but I couldn't move or see my hand to see what I was holding. There was no crash report, because I never crashed. I sat like that for over an hour before I got annoyed and came to report it.

Steps to reproduce:
1. Have someone open a single player world to LAN
2. Join the single player world.