Major So this issue is a bit odd.
Basically, an NPE is thrown when attempting to use event.getInventory.getOwner() on a PrepareItemCraftEvent that was fired by... Breeding sheep?
I'm not sure why a crafting inventory is used to determine the color of the new sheep, but I think Spigot should at least be returning null for something like this instead of causing all kinds of problems with internal NPEs.
