Small fix

init.lua

@@ -702,13 +702,15 @@ end
 
 local function cache_recipes(item)
 	item = reg_aliases[item] or item
+	local def = reg_items[item]
+	if not def then return end
 
 	local recipes = get_all_recipes(item) or {}
 	if #recipes > 0 then
 		recipes_cache[item] = recipes
 	end
 
-	cache_drops(item, reg_items[item].drop)
+	cache_drops(item, def.drop)
 	cache_fuel(item)
 end