diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/ImporterContext.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/ImporterContext.cs
index 968490559..d4eaac827 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/ImporterContext.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/ImporterContext.cs
@@ -339,6 +339,7 @@ namespace UniGLTF
         {
             if (index < 0 || index >= Nodes.Count)
             {
+                Debug.LogWarning($"nodes[{index}] is not found !");
                 node = default;
                 return false;
             }
diff --git a/Assets/VRM/Editor/SpringBone/VRMSpringBoneUtilityEditor.cs b/Assets/VRM/Editor/SpringBone/VRMSpringBoneUtilityEditor.cs
index 693a72a8f..439235827 100644
--- a/Assets/VRM/Editor/SpringBone/VRMSpringBoneUtilityEditor.cs
+++ b/Assets/VRM/Editor/SpringBone/VRMSpringBoneUtilityEditor.cs
@@ -97,6 +97,7 @@ namespace VRM
             {
                 if (index < 0 || index >= nodes.Count)
                 {
+                    Debug.LogWarning($"nodes[{index}] is not found !");
                     node = default;
                     return false;
                 }