diff --git a/core/src/main/java/net/momirealms/craftengine/core/item/ItemSettings.java b/core/src/main/java/net/momirealms/craftengine/core/item/ItemSettings.java
index 2800dcfc5..08e4310c5 100644
--- a/core/src/main/java/net/momirealms/craftengine/core/item/ItemSettings.java
+++ b/core/src/main/java/net/momirealms/craftengine/core/item/ItemSettings.java
@@ -399,6 +399,9 @@ public class ItemSettings {
             registerFactory("equippable", (value -> {
                 Map<String, Object> args = MiscUtils.castToMap(value, false);
                 EquipmentData data = EquipmentData.fromMap(args);
+                if (data.assetId() == null) {
+                    throw new IllegalArgumentException("Please move 'equippable' option to 'data' section.");
+                }
                 ComponentBasedEquipment componentBasedEquipment = ComponentBasedEquipment.FACTORY.create(data.assetId(), args);
                 ((AbstractItemManager<?>) CraftEngine.instance().itemManager()).addOrMergeEquipment(componentBasedEquipment);
                 ItemEquipment itemEquipment = new ItemEquipment(Tristate.FALSE, data, componentBasedEquipment);
diff --git a/core/src/main/java/net/momirealms/craftengine/core/item/equipment/AbstractEquipment.java b/core/src/main/java/net/momirealms/craftengine/core/item/equipment/AbstractEquipment.java
index bc315c190..7d0428166 100644
--- a/core/src/main/java/net/momirealms/craftengine/core/item/equipment/AbstractEquipment.java
+++ b/core/src/main/java/net/momirealms/craftengine/core/item/equipment/AbstractEquipment.java
@@ -8,11 +8,11 @@ public abstract class AbstractEquipment implements Equipment {
     protected final Key assetId;
 
     protected AbstractEquipment(Key assetId) {
-        this.assetId = Objects.requireNonNull(assetId, "assetId cannot be null");
+        this.assetId = Objects.requireNonNull(assetId, "asset-id cannot be null");
     }
 
     @Override
     public Key assetId() {
-        return assetId;
+        return this.assetId;
     }
 }
diff --git a/core/src/main/java/net/momirealms/craftengine/core/item/equipment/ComponentBasedEquipment.java b/core/src/main/java/net/momirealms/craftengine/core/item/equipment/ComponentBasedEquipment.java
index f60d497de..079732a56 100644
--- a/core/src/main/java/net/momirealms/craftengine/core/item/equipment/ComponentBasedEquipment.java
+++ b/core/src/main/java/net/momirealms/craftengine/core/item/equipment/ComponentBasedEquipment.java
@@ -143,5 +143,21 @@ public class ComponentBasedEquipment extends AbstractEquipment implements Suppli
                 return dyeData;
             }
         }
+
+        @Override
+        public @NotNull String toString() {
+            return "Layer{" +
+                    "texture='" + texture + '\'' +
+                    ", data=" + data +
+                    ", usePlayerTexture=" + usePlayerTexture +
+                    '}';
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "ComponentBasedEquipment{" +
+                "layers=" + this.layers +
+                '}';
     }
 }
diff --git a/core/src/main/java/net/momirealms/craftengine/core/pack/AbstractPackManager.java b/core/src/main/java/net/momirealms/craftengine/core/pack/AbstractPackManager.java
index a5429d220..1aa740527 100644
--- a/core/src/main/java/net/momirealms/craftengine/core/pack/AbstractPackManager.java
+++ b/core/src/main/java/net/momirealms/craftengine/core/pack/AbstractPackManager.java
@@ -1915,6 +1915,11 @@ public abstract class AbstractPackManager implements PackManager {
 
     private void processComponentBasedEquipment(ComponentBasedEquipment componentBasedEquipment, Path generatedPackPath) {
         Key assetId = componentBasedEquipment.assetId();
+        if (assetId == null) {
+            this.plugin.logger().severe("Asset id is null for equipment " + componentBasedEquipment);
+            return;
+        }
+
         if (Config.packMaxVersion().isAtOrAbove(MinecraftVersions.V1_21_4)) {
             Path equipmentPath = generatedPackPath
                     .resolve("assets")