Ray's changes in structure

app/models/item.rb

@@ -4,7 +4,7 @@ class Item
   include Mongoid::Timestamps
   include Mongoid::Tree
   include Mongoid::Tree::Ordering
-  LIST = YAML.load(File.read('config/list.yml'))
+  LIST = YAML.load(File.read("#{Rails.root}/config/list.yml"))
 
   field :name
   field :path