My server got crashed when someone is fighting the Obsidilith, I believe it because of the boss not landing on a flat surface when using the skill.

Here is the logs:
https://mclo.gs/zksHxnO

The crash basically says that when trying to create the loot chest/shulker box when it was defeated, it tried to create some sort of enchanted item and that crashed it. The loot is based on minecraft:chests/end_city_treasure, so I think the chests in end cities would may have the same problem sometimes