diff --git a/Assets/VRM10/Editor/MigrationMenu.cs b/Assets/VRM10/Editor/MigrationMenu.cs
index d62cb76d8..d497f79a8 100644
--- a/Assets/VRM10/Editor/MigrationMenu.cs
+++ b/Assets/VRM10/Editor/MigrationMenu.cs
@@ -13,11 +13,10 @@ namespace UniVRM10
         [MenuItem(CONTEXT_MENU, true)]
         static bool Enable()
         {
-            if (Selection.activeObject == null)
+            if (!VRMShaders.PathObject.TryGetFromAsset(Selection.activeObject, out VRMShaders.PathObject path))
             {
                 return false;
             }
-            var path = VRMShaders.PathObject.FromAsset(Selection.activeObject);
             var isVrm = path.Extension.ToLower() == ".vrm";
             return isVrm;
         }
@@ -25,7 +24,10 @@ namespace UniVRM10
         [MenuItem(CONTEXT_MENU, false)]
         static void Exec()
         {
-            var path = VRMShaders.PathObject.FromAsset(Selection.activeObject);
+            if (!VRMShaders.PathObject.TryGetFromAsset(Selection.activeObject, out VRMShaders.PathObject path))
+            {
+                return;
+            }
 
             // migrate
             var vrm1Bytes = MigrationVrm.Migrate(path.ReadAllBytes());
diff --git a/Assets/VRMShaders/GLTF/IO/Editor/PathObject.cs b/Assets/VRMShaders/GLTF/IO/Editor/PathObject.cs
index aef30c3b1..56efe3a9c 100644
--- a/Assets/VRMShaders/GLTF/IO/Editor/PathObject.cs
+++ b/Assets/VRMShaders/GLTF/IO/Editor/PathObject.cs
@@ -33,14 +33,14 @@ namespace VRMShaders
         /// Application.dataPath は Assets を得る。
         /// </summary>
         /// <returns></returns>
-        public string UnityPath
+        public string UnityAssetPath
         {
             get
             {
                 var root = UnityRoot;
                 if (!IsDescendantOf(UnityRoot))
                 {
-                    throw new ArgumentException($"{FullPath} is not under UnityPath");
+                    throw new ArgumentException($"{FullPath} is not under UnityAssetPath");
                 }
                 return FullPath.Substring(root.FullPath.Length + 1);
             }
@@ -94,8 +94,8 @@ namespace VRMShaders
         {
             try
             {
-                var unityPath = UnityPath;
-                return $"<unity:{unityPath}>";
+                var assetPath = UnityAssetPath;
+                return $"<unity:{assetPath}>";
             }
             catch (ArgumentException)
             {
@@ -112,23 +112,28 @@ namespace VRMShaders
 
         /// <param name="src">AssetDatabase が使うパス</param>
         /// <returns></returns>
-        public static PathObject FromUnityPath(string src)
+        public static PathObject FromUnityAssetPath(string src)
         {
             return UnityRoot.Child(src);
         }
 
-        public static PathObject FromAsset(UnityEngine.Object src)
+        public static bool TryGetFromAsset(UnityEngine.Object src, out PathObject dst)
         {
             if (src == null)
             {
-                throw new ArgumentNullException();
+                dst = default;
+                return false;
             }
+
             var assetPath = AssetDatabase.GetAssetPath(src);
             if (string.IsNullOrEmpty(assetPath))
             {
-                throw new ArgumentException($"{src} is not asset");
+                dst = default;
+                return false;
             }
-            return FromUnityPath(assetPath);
+
+            dst = FromUnityAssetPath(assetPath);
+            return true;
         }
 
         public PathObject Child(string child)
@@ -161,7 +166,7 @@ namespace VRMShaders
 
         public void ImportAsset()
         {
-            AssetDatabase.ImportAsset(UnityPath);
+            AssetDatabase.ImportAsset(UnityAssetPath);
         }
 
         public bool TrySaveDialog(string title, string name, out PathObject dst)
diff --git a/Assets/VRMShaders/GLTF/IO/Tests/PathObjectTests.cs b/Assets/VRMShaders/GLTF/IO/Tests/PathObjectTests.cs
index 04028497f..1a14bda0d 100644
--- a/Assets/VRMShaders/GLTF/IO/Tests/PathObjectTests.cs
+++ b/Assets/VRMShaders/GLTF/IO/Tests/PathObjectTests.cs
@@ -22,7 +22,7 @@ namespace VRMShaders
 
             Assert.AreEqual(PathObject.UnityRoot.Child("Assets"), PathObject.UnityAssets);
             Assert.AreEqual(PathObject.UnityAssets.Parent, PathObject.UnityRoot);
-            Assert.AreEqual("Assets", PathObject.UnityAssets.UnityPath);
+            Assert.AreEqual("Assets", PathObject.UnityAssets.UnityAssetPath);
         }
     }
 }