https://youtu.be/bAiNfFI4K7s

Chests occasionally contain blank enchanted books.
Mods folder w/ error in video to show possible conflicting mods.

I don't think this is really something I can fix on my end, the enchanted books in the loot pools are added via the vanilla enchant randomly function, which selects a random enchantment from the registry and places it on a book.