Update app_main.py

app_main.py

@@ -372,7 +372,10 @@ def similarity_matching(input_json_path: str) -> str:
         
     img_matrix = np.array([img["embeddings"] for img in embedding_json])
     sprite_matrix = np.array(sprite_features)
-    
+
+    if sprite_matrix.size == 0 or img_matrix.size == 0:
+        raise RuntimeError("❌ No valid embeddings found for sprites or reference images.")
+        
     try:
         similarity = np.matmul(sprite_matrix, img_matrix.T)
     except ValueError as ve: