See this video: https://www.youtube.com/watch?v=Lny6Ri7y_y8
Command used in the video:
/summon phantom ~ ~10 ~ {Size:5,Passengers:[{id:"pig",Saddle:1,ActiveEffects:[{Id:14,Amplifier:0,Duration:199980,ShowParticles:0b}
The Bug
While riding the entity summoned by the command above and than killing all the entities exept for players, the internal server of a single player world is shut down, similar to the elytra glith in MC-122354, but the disconnection is faster and the player is unable to enter the world anymore.
How to Reproduce
Sommon a ridable phantom using the command above.
Ride it.
/kill @e[type=!player]
Say goodbye to your world.
Linked issues
Comments 3
Can't reproduce, maybe it has already been fixed
Didn't kick in 18w22c, too.
CivetKitty
I don't know if I was lucky, but I was able to get back into my world after the game crashed in 18w11a, but the crash upon following the steps provided is still an issue.