CanPlaceOn and CanBreak don't work

Summary

I have been testing around with CanBreak and CanPlaceOn in the files, but every time I try it out it gives me the error that the item is not properly configurated and it returned to null. I have used the examples from the wiki and tried out many options, but it either doesn't work at all or just completely breaks. Please note I am using MythicMobs on Aternos!

Steps to reproduce

Really it's just create any item with the CanBreak and/or the CanPlaceOn prompts.

Current behavior

An error pops up saying 'Could not get item: item is improperly configurated and returned to null.'

Intended correct behavior

If I use "/mm i get " that has the prompts in its code, it should give me the item like with any other and have the working attributes.

Server log file

LOG 1 https://pastebin.com/UbUPWYxT

LOG 2 https://pastebin.com/bYHJKv8v

HOW THE CODE LOOKS https://pastebin.com/PBTrHVBS

Debug log snippet

I'm a little lost here... Sorry :/

Proposed fixes

It should simply give me the item without errors and work like intended... right?