diff --git a/Assets/VRM10/Editor/Components/VRM10Window.cs b/Assets/VRM10/Editor/Components/VRM10Window.cs
index c82e848ff..5bf93747b 100644
--- a/Assets/VRM10/Editor/Components/VRM10Window.cs
+++ b/Assets/VRM10/Editor/Components/VRM10Window.cs
@@ -64,8 +64,11 @@ namespace UniVRM10
                 m_so = value != null ? new SerializedObject(value) : null;
                 m_constraints = null;
 
-                var animator = Root.GetComponent<Animator>();
-                m_head = animator.GetBoneTransform(HumanBodyBones.Head);
+                if (Root != null)
+                {
+                    var animator = Root.GetComponent<Animator>();
+                    m_head = animator.GetBoneTransform(HumanBodyBones.Head);
+                }
             }
         }