If you join a server (I think it works with any server), leave and then reconnect but then cancel before you log in and quickly join a singleplayer world you will log into the world on the server, falling through the ground and if you exit the world because you don't want to lose your stuff your game will crash. This bug is consistent and you can try it, don't worry both worlds won't be damaged (from what it seems).
Linked issues
duplicates
Comments
[Mod] markderickson
Hi there!
This looks like a duplicate of MC-74984.
Also, in the future, make sure you can reproduce a bug on a pure vanilla server/client (no Optifine, Spigot, etc). It will be marked as Invalid otherwise.