error checking for evaluate_model

app.py

@@ -491,13 +491,14 @@ def update_leaderboard(username, zip_file):
     try:
         updated_leaderboard = evaluate_model(username, python_script)
 
-        if update_leaderboard == None:
-            return None
     except Exception as e:
         print("Error in eval mode:", str(e))
         return f"Error evaluating model: {str(e)}", None
 
     # log_submission_request(username, zip_file)
+    if updated_leaderboard == None:
+        return None
+        
     set_error_message("Submission successful!")
     return "Submission successful!", updated_leaderboard