diff --git a/Assets/_DDD/_Scripts/AssetPostprocessors/AssetPostprocessorSprite.cs b/Assets/_DDD/_Scripts/AssetPostprocessors/AssetPostprocessorSprite.cs
index aa7773680..1c4c17d5e 100644
--- a/Assets/_DDD/_Scripts/AssetPostprocessors/AssetPostprocessorSprite.cs
+++ b/Assets/_DDD/_Scripts/AssetPostprocessors/AssetPostprocessorSprite.cs
@@ -203,6 +203,13 @@ public static void CreateAtlas(string path, string destPath)
 
             if (objects.Count == 0) return;
 
+            // Validate destination path extension
+            if (!destPath.EndsWith(ExtenstionConstants.SpriteAtlasExtenstionLower, System.StringComparison.OrdinalIgnoreCase))
+            {
+                Debug.LogWarning($"[SpriteAtlas] destPath must end with .spriteatlas : {destPath}");
+                return;
+            }
+
             Utils.MakeFolderFromFilePath(destPath);
             var atlas = new SpriteAtlasAsset();
 
@@ -216,9 +223,17 @@ public static void CreateAtlas(string path, string destPath)
             atlas.Add(objects.ToArray());
 
             SpriteAtlasAsset.Save(atlas, destPath);
-            AssetDatabase.Refresh();
 
-            var sai = (SpriteAtlasImporter)AssetImporter.GetAtPath(destPath);
+            // Ensure importer is created/applied synchronously before accessing it
+            AssetDatabase.ImportAsset(destPath, ImportAssetOptions.ForceUpdate | ImportAssetOptions.ForceSynchronousImport);
+
+            var sai = AssetImporter.GetAtPath(destPath) as SpriteAtlasImporter;
+            if (sai == null)
+            {
+                Debug.LogWarning($"[SpriteAtlas] Importer not ready for '{destPath}'. Skipping settings this pass.");
+                return;
+            }
+
             sai.packingSettings = new SpriteAtlasPackingSettings
             {
                 enableRotation = false,
@@ -235,8 +250,11 @@ public static void CreateAtlas(string path, string destPath)
                 generateMipMaps = false
             };
 
-            // 저장 후 설정 반영을 위해 동기 임포트, 그리고 즉시 패킹 수행
+            // Persist settings and reimport synchronously to apply them
+            AssetDatabase.WriteImportSettingsIfDirty(destPath);
             AssetDatabase.ImportAsset(destPath, ImportAssetOptions.ForceUpdate | ImportAssetOptions.ForceSynchronousImport);
+
+            // Finally, pack the atlas for the active build target
             var packedAtlas = AssetDatabase.LoadAssetAtPath<SpriteAtlas>(destPath);
             if (packedAtlas != null)
             {
@@ -253,10 +271,22 @@ public static void CreateSingleAtlas(string path, string destPath)
                 AssetDatabase.DeleteAsset(destPath);
             }
 
+            // Validate destination path extension
+            if (!destPath.EndsWith(ExtenstionConstants.SpriteAtlasExtenstionLower, System.StringComparison.OrdinalIgnoreCase))
+            {
+                Debug.LogWarning($"[SpriteAtlas] destPath must end with .spriteatlas : {destPath}");
+                return;
+            }
+
             Utils.MakeFolderFromFilePath(destPath);
             var atlas = new SpriteAtlasAsset();
 
             var sprite = AssetDatabase.LoadAssetAtPath<Sprite>(path);
+            if (sprite == null)
+            {
+                Debug.LogWarning($"[SpriteAtlas] Source sprite not found at '{path}'. Skipping atlas: '{destPath}'");
+                return;
+            }
             atlas.Add(new Object[] { sprite });
 
             var spriteAtlasComponents = new List<IPostProcessorSpriteAtlas>();
@@ -267,9 +297,17 @@ public static void CreateSingleAtlas(string path, string destPath)
             }
 
             SpriteAtlasAsset.Save(atlas, destPath);
-            AssetDatabase.Refresh();
 
-            var sai = (SpriteAtlasImporter)AssetImporter.GetAtPath(destPath);
+            // Ensure importer is created/applied synchronously before accessing it
+            AssetDatabase.ImportAsset(destPath, ImportAssetOptions.ForceUpdate | ImportAssetOptions.ForceSynchronousImport);
+
+            var sai = AssetImporter.GetAtPath(destPath) as SpriteAtlasImporter;
+            if (sai == null)
+            {
+                Debug.LogWarning($"[SpriteAtlas] Importer not ready for '{destPath}'. Skipping settings this pass.");
+                return;
+            }
+
             sai.packingSettings = new SpriteAtlasPackingSettings
             {
                 enableRotation = false,
@@ -286,8 +324,11 @@ public static void CreateSingleAtlas(string path, string destPath)
                 generateMipMaps = false
             };
 
-            // 저장 후 설정 반영을 위해 동기 임포트, 그리고 즉시 패킹 수행
+            // Persist settings and reimport synchronously to apply them
+            AssetDatabase.WriteImportSettingsIfDirty(destPath);
             AssetDatabase.ImportAsset(destPath, ImportAssetOptions.ForceUpdate | ImportAssetOptions.ForceSynchronousImport);
+
+            // Finally, pack the atlas for the active build target
             var packedAtlas = AssetDatabase.LoadAssetAtPath<SpriteAtlas>(destPath);
             if (packedAtlas != null)
             {