Correct. If you look at the recipe setup:
RECIPES = {
0 => { :result => [0,1,1],
:materials => [[0,4,2]],
:gold_cost => 10,
:success => 95,
:success_gain => 1,
:level => 5,
:craft_level => 1,
:category => :Baking,
:xp => 50,
:xp_deprac => 15,},
1 => { :result => [0,2,1],
:materials => [[0,4,1],[0,5,2,false]],
:gold_cost => 50,
:success => 90,
:success_gain => 2,
:level => 15,
:craft_level => 1,
:category => :Baking,
:xp => 150,
:xp_deprac => 20,},
2 => { :result => [0,3,1],
:materials => [[0,4,1],[0,5,1],[0,6,2],[0,7,1],[0,8,1],[0,9,2]],
:gold_cost => 150,
:success => 85,
:success_gain => 3,
:level => 25,
:craft_level => 1,
:category => :Baking,
:xp => 250,
:xp_deprac => 25,},
}
So recipe 0 creates 1 of item #1, requiring 2 of item #4; recipe 1 creates 1 of item #2, requiring 1 of item #4 and 2 of item #5; recipe 2 creates 1 of item #3, requiring 1 of item #4, 1 of item #5, 2 of item #6, 1 of item #7, 1 of item #8 and 2 of item #9.
The thing is, your database only has two items right now, Cupcake and Cupcake Recipe. The script is looking at your defined recipes and going "Okay, so this recipe needs this many of item #4. I need to show the icon for item #4...where is item #4? You don't have one!" *crash*
Make sense?