Use exact reference structure with demo.queue().launch()

app.py

@@ -163,7 +163,10 @@ def build_state_dataframe(metadata: dict, end_effector: dict, hand: str = "left"
     """Build state dataframe from JSON data."""
     fps = metadata.get('fps', 60)
     
-    frame_keys = sorted([int(k) for k in end_effector.keys() if str(k).isdigit()])
+    try:
+        frame_keys = sorted([int(k) for k in end_effector.keys() if str(k).isdigit()])
+    except:
+        frame_keys = []
     
     timestamps = []
     state_data = {