When I was playing with friends, I spawned near the bonus chest(normal) and I walked the direction that my friend said the village was in when I saw a giant rectangular hole. It appeared that I could see The Void. It has not happened much times before, so it must be Random. It also appeared that my friends were flying. I also had unlimited dirt. When I placed  the dirt, Two blocks appeared and I could walk on them.

This is all the same problem: I can fall into The Void.

Randomly reproduces.