[player] was kicked for floating too long!

in singleplayer. when i died. it kick me and my minecraft not responding!
Here the document!

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 punch.
Wait for a few seconds at the death screen.
Your game is now frozen.