If a player dies on the ground but their corpse flies into the sky for long enough (typically from a large explosion), the player is kicked from the internal server on suspicion of fly-hacking. On a Singleplayer game, this will crash Minecraft. The server logs read:

[Server thread/WARN]: UserName was kicked for floating too long!
[Server thread/INFO]: UserName lost connection: TextComponent{text='Disconnected', siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null, insertion=null}}
[Server thread/INFO]: UserName left the game

followed by normal server closing procedure, indicating that the internal server is unaffected by the crash.

Steps to reproduce:

• Start a Singleplayer Creative game.
• Run the command /gamemode s.
• Run the command /summon EnderCrystal four or more times.
• Look down and puch.
• Wait for a few seconds at the death screen.
• Notice that your game is now frozen.

After testing I determined that this bug first occured in 15w42a, although the bug tracker won't let me list that as an affected version.