diff --git a/Assets/ModelRenderer/Editor/CombineActionSOAssigner.cs b/Assets/ModelRenderer/Editor/CombineActionSOAssigner.cs
index e7040e863f..5fe1ff8806 100644
--- a/Assets/ModelRenderer/Editor/CombineActionSOAssigner.cs
+++ b/Assets/ModelRenderer/Editor/CombineActionSOAssigner.cs
@@ -1,6 +1,7 @@
 // UTF-8 with BOM — required for Chinese character paths
 using System.Collections.Generic;
 using System.IO;
+using System.Text;
 using BrewMonster.Scripts.ECModel;
 using UnityEditor;
 using UnityEngine;
@@ -10,10 +11,14 @@ public class CombineActionSOAssigner : EditorWindow
     // Fixed — this is always where the weapon prefabs live
     private const string PrefabRootPath = "Assets/ModelRenderer/Art/Models/models/weapons";
 
+    // Log files land next to the project's Logs/ folder
+    private static readonly string LogDir = Path.GetFullPath("Logs/SOAssigner");
+
     private string _soRootPath = "Assets/ModelRenderer/Art/Models/models/weapons";
     private bool _isDryRun = true;
     private Vector2 _scrollPos;
     private readonly List<string> _log = new();
+    private string _lastLogFile;
 
     private static readonly GUIStyle HeaderStyle = new(EditorStyles.boldLabel)
     {
@@ -94,10 +99,18 @@ public class CombineActionSOAssigner : EditorWindow
     {
         EditorGUILayout.BeginHorizontal();
         EditorGUILayout.LabelField("Log", EditorStyles.boldLabel);
+        if (!string.IsNullOrEmpty(_lastLogFile) && GUILayout.Button("Open Log File", GUILayout.Width(100)))
+            EditorUtility.RevealInFinder(_lastLogFile);
         if (GUILayout.Button("Clear", GUILayout.Width(60)))
+        {
             _log.Clear();
+            _lastLogFile = null;
+        }
         EditorGUILayout.EndHorizontal();
 
+        if (!string.IsNullOrEmpty(_lastLogFile))
+            EditorGUILayout.LabelField(_lastLogFile, EditorStyles.miniLabel);
+
         _scrollPos = EditorGUILayout.BeginScrollView(_scrollPos, GUILayout.ExpandHeight(true));
         foreach (var line in _log)
             EditorGUILayout.LabelField(line, EditorStyles.wordWrappedLabel);
@@ -121,6 +134,7 @@ public class CombineActionSOAssigner : EditorWindow
 
         string[] guids = AssetDatabase.FindAssets("t:Prefab", new[] { PrefabRootPath });
         int orphans = 0;
+        var fileLines = new List<string> { $"=== ORPHAN CHECK  {Timestamp()} ===" };
 
         foreach (string guid in guids)
         {
@@ -129,24 +143,36 @@ public class CombineActionSOAssigner : EditorWindow
 
             if (AssetDatabase.LoadAssetAtPath<CombinedActionSO>(soPath) == null)
             {
-                _log.Add($"[ORPHAN]  {Path.GetFileNameWithoutExtension(prefabPath)}");
-                _log.Add($"          expected SO: {soPath}");
+                string line1 = $"[ORPHAN]  {Path.GetFileNameWithoutExtension(prefabPath)}";
+                string line2 = $"          expected SO: {soPath}";
+                _log.Add(line1);
+                _log.Add(line2);
+                fileLines.Add(line1);
+                fileLines.Add(line2);
                 orphans++;
             }
         }
 
-        _log.Add($"=== {orphans} orphan(s) out of {guids.Length} prefab(s) ===");
+        string summary = $"=== {orphans} orphan(s) out of {guids.Length} prefab(s) ===";
+        _log.Add(summary);
+        fileLines.Add(summary);
+
+        _lastLogFile = WriteLogFile("OrphanCheck", fileLines);
+        Debug.Log($"[SO Assigner] Orphan Check — {orphans}/{guids.Length} orphans. Log: {_lastLogFile}");
         Repaint();
     }
 
     private void RunAssignment()
     {
         _log.Clear();
-        _log.Add(_isDryRun ? "=== DRY RUN ===" : "=== LIVE RUN ===");
+        string header = _isDryRun ? "=== DRY RUN ===" : "=== LIVE RUN ===";
+        _log.Add(header);
 
         string[] guids = AssetDatabase.FindAssets("t:Prefab", new[] { PrefabRootPath });
         int matched = 0, skipped = 0, failed = 0;
 
+        var fileLines = new List<string> { $"{header}  {Timestamp()}" };
+
         try
         {
             for (int i = 0; i < guids.Length; i++)
@@ -163,26 +189,32 @@ public class CombineActionSOAssigner : EditorWindow
                 CombinedActionSO so = AssetDatabase.LoadAssetAtPath<CombinedActionSO>(soPath);
                 if (so == null)
                 {
-                    _log.Add($"[SKIP]  {prefabName}  →  no SO at: {soPath}");
+                    string skipLine = $"[SKIP]  {prefabName}  →  {soPath}";
+                    fileLines.Add(skipLine);
+                    if (!_isDryRun)
+                        _log.Add(skipLine); // window only gets skips in live mode
                     skipped++;
                     continue;
                 }
 
                 if (_isDryRun)
                 {
-                    _log.Add($"[MATCH]  {prefabName}  →  {soPath}");
+                    // File gets every match; window stays quiet
+                    fileLines.Add($"[MATCH]  {prefabName}  →  {soPath}");
                     matched++;
                 }
                 else
                 {
                     if (!TryAssign(prefabPath, so, out string error))
                     {
-                        _log.Add($"[ERROR]  {prefabName}  —  {error}");
+                        string errLine = $"[ERROR]  {prefabName}  —  {error}";
+                        _log.Add(errLine);
+                        fileLines.Add(errLine);
                         failed++;
                     }
                     else
                     {
-                        _log.Add($"[OK]  {prefabName}");
+                        fileLines.Add($"[OK]  {prefabName}");
                         matched++;
                     }
                 }
@@ -203,7 +235,18 @@ public class CombineActionSOAssigner : EditorWindow
         if (!_isDryRun)
             AssetDatabase.SaveAssets();
 
-        _log.Add($"=== DONE — matched: {matched}, skipped: {skipped}, failed: {failed} (total: {guids.Length}) ===");
+        string summary = $"matched: {matched}, skipped: {skipped}, failed: {failed} (total: {guids.Length})";
+        string summaryLine = $"=== DONE — {summary} ===";
+        _log.Add(summaryLine);
+        fileLines.Add(summaryLine);
+
+        _lastLogFile = WriteLogFile(_isDryRun ? "DryRun" : "LiveRun", fileLines);
+
+        Debug.Log($"[SO Assigner] {(_isDryRun ? "DRY RUN" : "LIVE")} — {summary}  |  Log: {_lastLogFile}");
+
+        if (skipped > 0)
+            Debug.LogWarning($"[SO Assigner] {skipped} unmatched prefab(s) — see log file for details: {_lastLogFile}");
+
         Repaint();
     }
 
@@ -248,6 +291,20 @@ public class CombineActionSOAssigner : EditorWindow
         }
     }
 
+    // ── File logging ─────────────────────────────────────────────────────────
+
+    private static string WriteLogFile(string prefix, List<string> lines)
+    {
+        Directory.CreateDirectory(LogDir);
+        string fileName = $"{prefix}_{System.DateTime.Now:yyyy-MM-dd_HH-mm-ss}.log";
+        string fullPath = Path.Combine(LogDir, fileName);
+        File.WriteAllLines(fullPath, lines, new UTF8Encoding(encoderShouldEmitUTF8Identifier: true));
+        return fullPath;
+    }
+
+    private static string Timestamp() =>
+        System.DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
+
     // ── Path helpers ─────────────────────────────────────────────────────────
 
     /// <summary>