The bug I seem to be experiencing is quite basic. I was using MCEdit with Minecraft closed to apply attributes to an item I had. I expected I would have my custom item normally in my hand. Instead, when I attempted to inspect the item in a chest, Minecraft would crash. I was about to burn the item by breaking the chest, but picked up the item instead! Now, everytime I open up my world, I crash! The entire attributes system was functional until that one attempt. Thank you for taking the time to read this.

1. Place item you wish to change in chest.
2. Enter MCEdit and apply attributes.
3. Exit Minecraft and attempt to inspect item.