Trading with a fletcher villager (sticks for emerald) causes the server to crash with the exception: java.lang.IllegalStateException: Removing entity while ticking!
This happens only if having Hero Of The Village active effect.
Reproduced many times on the server, crashes every time.
After drinking milk and getting rid of the effect - no more crashes.
NO PLUGINS

Full crash report attached.

The issue is not happening if recreated on a single player Minecraft.