Use /kill @e[type=EnderCrystal] instruction, rebirth ceremony continued execution.
Video:
https://www.youtube.com/watch?v=Ui8kmCkk-z8
https://www.youtube.com/watch?v=vZlIy1Oq-90
Environment
OS : Windows 10 64-bit
Java 8 version : 1.8.0_66-b18 64-bit
CPU : Intel(R) Core(TM) i5-4460 CPU @ 3.20GHz
GPU : NVIDIA GeForce GTX 650
Drivers : GeForce 359.00
Linked issues
relates to 4
MC-91641
Beam target of ender crystals used for ender dragon spawn sequence do not update after unloading
Resolved
MC-91636
Ender dragon spawn sequence freezes when you reload the world
Resolved
MC-91748
Ender Crystal overlap when interrupting the Dragon rebirth sequence
Resolved
MC-91756
Beam target of ender crystals on obsidian pillars does not update when ender dragon spawn sequence is stopped
Resolved
Relates to:
MC-91636
MC-91641
MC-91756
MC-91748