Second part of fix try stupid bug

mods/ITEMS/mcl_armor/api.lua

@@ -111,7 +111,7 @@ function mcl_armor.register_set(def)
 		groups.mcl_armor_toughness = def.toughness
 		groups.mcl_armor_uses = (durabilities[name] or math.floor(def.durability * element.durability)) + 1
 		groups.enchantability = def.enchantability
-		groups.upgradable = def.upgradable
+		groups._mcl_upgradable = def._mcl_upgradable
 
 		for k, v in pairs(element_groups) do
 			groups[k] = v
@@ -136,6 +136,7 @@ function mcl_armor.register_set(def)
 			_mcl_armor_element = name,
 			_mcl_armor_texture = textures[name] or modname .. "_" .. itemname .. ".png",
 			_mcl_armor_preview = previews[name] or modname .. "_" .. itemname .. "_preview.png",
+			_mcl_upgradable = def._mcl_upgradable
 		})
 
 		if def.craft_material then

mods/ITEMS/mcl_armor/register.lua

@@ -79,7 +79,7 @@ mcl_armor.register_set({
 	},
 	toughness = 2,
 	craft_material = "mcl_core:diamond",
-	upgradable = true
+	_mcl_upgradable = true
 })
 
 mcl_armor.register_set({