Obtaining 9 charcoal unlocks the Block of Coal recipe (as well as the Coal recipe, obtained from blocks of coal). Presumably, this should only happen when you obtain 9 coal.
Obtaining 9 charcoal unlocks the Block of Coal recipe (as well as the Coal recipe, obtained from blocks of coal). Presumably, this should only happen when you obtain 9 coal.
This looks like a simple problem of the advacement for the recipe not specifing the data in the json file.