Added some error checks to prevent an invalid box from being loaded
Jukebox Songs
If you disable the resource pack, players will be able to unlock and select songs - very useful in case you want to include songs in your own global resource pack
List Loots Command
If a loot happens to not be loaded, you can now see what is causing the problem - here's an example: https://i.imgur.com/EY20vEV.png