I've crashed multiple times now and I've even lost an enchanted diamond pickaxe as a result of this crash. It happens every time I attempt to add an enchantment book to my weapon in an anvil.

Keep in mind that I have 104 mods running in the game so that could also be the issue.

Here is the crash log

crash-2018-03-14_08.49.18-client.txt

Does one of the mods mess with the enchanting mechatic? Try to disable few suspicious mods, and may I ask what version of mc and forge are you using?

It all should be in the text document but ill tell you anyway

Minecraft Version: 1.12.2

Forge Version: 14.23.2.2611

It seems that disabling Ancient tomes fixes the problem. I'm ok now but if you'd like, you can use the text file and find away to fix this bug.