diff --git a/Scripts/BlendShape/Editor/BlendShapeAvatarEditor.cs b/Scripts/BlendShape/Editor/BlendShapeAvatarEditor.cs
index e87e43682..7f76f52f0 100644
--- a/Scripts/BlendShape/Editor/BlendShapeAvatarEditor.cs
+++ b/Scripts/BlendShape/Editor/BlendShapeAvatarEditor.cs
@@ -57,7 +57,7 @@ namespace VRM
                 }
             };
 
-            m_clipList.onCanRemoveCallback += list => true;
+            //m_clipList.onCanRemoveCallback += list => true;
         }
 
         void OnDisable()
diff --git a/Scripts/BlendShape/Editor/BlendShapeClipEditor.cs b/Scripts/BlendShape/Editor/BlendShapeClipEditor.cs
index 8cd8bbad6..440076e86 100644
--- a/Scripts/BlendShape/Editor/BlendShapeClipEditor.cs
+++ b/Scripts/BlendShape/Editor/BlendShapeClipEditor.cs
@@ -91,7 +91,10 @@ namespace VRM
 
         public override void OnInspectorGUI()
         {
-            base.OnInspectorGUI();
+            if (PreviewSceneManager == null)
+            {
+                return;
+            }
 
             if (m_serializedEditor == null)
             {
@@ -100,12 +103,14 @@ namespace VRM
                 m_isBinaryProp = serializedObject.FindProperty("IsBinary");
             }
 
+            int thumbnailSize = 96;
             EditorGUILayout.BeginHorizontal();
             EditorGUILayout.ObjectField(m_thumbnailProp.objectReferenceValue, typeof(Texture), false,
-                GUILayout.Width(64), GUILayout.Height(64));
+                GUILayout.Width(thumbnailSize), GUILayout.Height(thumbnailSize));
 
             var changed = false;
             EditorGUILayout.BeginVertical();
+            base.OnInspectorGUI();
             EditorGUILayout.LabelField("Preview Weight");
             var previewSlider = EditorGUILayout.Slider(m_previewSlider, 0, 1.0f);
             GUI.enabled = PreviewTexture != null;
@@ -141,6 +146,7 @@ namespace VRM
             }
 
             EditorGUILayout.EndHorizontal();
+            Separator();
             EditorGUILayout.Space();
 
             var result = m_serializedEditor.Draw();
diff --git a/Scripts/BlendShape/Editor/PreviewEditor.cs b/Scripts/BlendShape/Editor/PreviewEditor.cs
index dd4bd9b1b..b00967fed 100644
--- a/Scripts/BlendShape/Editor/PreviewEditor.cs
+++ b/Scripts/BlendShape/Editor/PreviewEditor.cs
@@ -156,9 +156,9 @@ namespace VRM
         {
             //base.OnInspectorGUI();
 
-            Prefab = (GameObject)EditorGUILayout.ObjectField("prefab for preview", Prefab, typeof(GameObject), false);
+            Prefab = (GameObject)EditorGUILayout.ObjectField("Preview Prefab", Prefab, typeof(GameObject), false);
 
-            Separator();
+            //Separator();
         }
 
         private static int sliderHash = "Slider".GetHashCode();