improve ui, error handling

app.py

@@ -90,22 +90,21 @@ def add_solution_cbk(
     if profile is None or token is None:
         return styled_error("Please sign in with Hugging Face before submitting.")
 
-    # Display handle and display name (good for the UI)
+    # Display handle and display name (may change over time)
     handle = profile.username
     logger.info(f"User handle: {handle}")
     display_name = profile.name or handle
     logger.info(f"Displaying name: {display_name}")
 
-    # Optional: verify handle/orgs via Hub API
-    info = whoami(token.token)  # {'name': 'user', 'orgs': [{'name': 'org1'}, ...], ...}
-    logger.info(f"User info: {info}")
-
-    # Stable account id (for dedup, enforcement, joins)
+    # Stable account id
     claims = fetch_sub_claim(token) or {}
     logger.info(f"Claims: {claims}")
     stable_id = claims.get("sub")
     logger.info(f"User stable ID: {stable_id}")
 
+    if not stable_id:
+        return styled_error("Could not retrieve your stable user ID. Please try signing in again.")
+
     try:
         # Validating the submission file.
         if len(submission_path) == 0:
@@ -218,7 +217,6 @@ with blocks:
             submit_panel = gr.Group(visible=False)
             with submit_panel:
                 with gr.Row():
-                    status_line = gr.Markdown()  # "Signed in as @user"
                     with gr.Column():
                         system_name_textbox = gr.Textbox(label=AutoEvalColumn.system.name)
                         org_textbox = gr.Textbox(label=AutoEvalColumn.organization.name)