CodeChickenLib version 3.1.9.344
Happened in the FTB Continuum pack version 1.3.1.
FTBTeam/FTB-Continuum#227

Both Blazes as well as Magma Cubes are affected by this. All "natural" overworld creatures as well as Ghasts and Wither Skeletons seem unaffected.

https://pastebin.com/SvS1dVYp
https://pastebin.com/JE8SWCn1

not only that mobs , the enderman too.
i have here the follow situation:

• big hole and a automated mob spawner
• now the Enderman falling in her dead, downwards upto the bad rock.
• short time later after i activated the spawner, the server crashes with the same error.

enderman ist here the problem mob

ownen modpack compilation,
forge 2707,
CodeChickenLib-1.12.2-3.1.9.344-universal

@mtimyself
check mob farms, or places who mobs can have unnaturally fast movement.
fall damage etc.

regards