I was exploring and came across a structure, I believe it was called "Mesa Ruins" and a chestloot was an enchanted book. Below the enchants:
It said "Loot Table Error - Report to Mod/Datapack Author, so here am I.

Hi, thank you for reporting this issue!
Do you know which mod might be the cause of this message? There doesn't seem to be enough context here for me to interpret what is going wrong.

Closing due to inactivity. Feel free to reopen :)