If Farmer's Delight and Neapolitan are installed together, it is no longer possible to craft the Farmer's Delight Milk Bottles. This makes it so that Delight addon mods that use FD Milk Bottles are uncraftable, as the Neapolitan Milk Bottles are treated as a separate item.

Neapolitan 5.0.0
Farmer's Delight 1.2.4

Didn't realize this was intentional and that a previous issue was opened on FD's issue page explaining it.