Is it possible to catch KeyError: st.session_state has no key "$$WIDGET_ID-..."?

Using Streamlit
1

KeyError happens after my service restarts while my user has the app open. This happens frequently as I push updates.

I’d like to catch this issue and automatically refresh the window. How do I catch this exception?

My app is multi-page with st.navigation, and I have this around my main function in my app_entry.py (file with st.navigation):

if __name__ == "__main__":
    try:
        main()
    except KeyError as e:
        logger.error(traceback.format_exc())
        streamlit_js_eval(js_expressions="parent.window.location.reload()")
        st.error(f"Frontend error! Try refreshing the page. Ask admin for help.")

But still it throws the KeyError without catching in the except KeyError block. Any way I can catch the KeyError?

Debugging info:

  1. Are you running your app locally or is it deployed? Deployed
  2. If your app is deployed:
    a. Is it deployed on Community Cloud or another hosting platform? AWS ECS
    b. Share the link to the public deployed app. It’s private
  3. Share the link to your app’s public GitHub repository (including a requirements file). It’s private.
  4. Share the full text of the error message (not a screenshot).
KeyError: 'st.session_state has no key "$$WIDGET_ID-4dd4a76c5c949c58634579cb344294f6-questionnaire_select_box". Did you forget to initialize it? More info: https://docs.streamlit.io/develop/concepts/architecture/session-state#initialization'
Traceback:

File "/usr/local/lib/python3.12/site-packages/streamlit/runtime/scriptrunner/exec_code.py", line 88, in exec_func_with_error_handling
    result = func()
             ^^^^^^
File "/usr/local/lib/python3.12/site-packages/streamlit/runtime/scriptrunner/script_runner.py", line 595, in code_to_exec
    self._session_state.maybe_check_serializable()
File "/usr/local/lib/python3.12/site-packages/streamlit/runtime/state/safe_session_state.py", line 74, in maybe_check_serializable
    self._state.maybe_check_serializable()
File "/usr/local/lib/python3.12/site-packages/streamlit/runtime/state/session_state.py", line 691, in maybe_check_serializable
    self._check_serializable()
File "/usr/local/lib/python3.12/site-packages/streamlit/runtime/state/session_state.py", line 679, in _check_serializable
    err_msg = f"""Cannot serialize the value (of type `{type(self[k])}`) of '{k}' in st.session_state.
                                                             ~~~~^^^
File "/usr/local/lib/python3.12/site-packages/streamlit/runtime/state/session_state.py", line 412, in __getitem__
    raise KeyError(_missing_key_error_message(key))
  1. Share the Streamlit and Python versions.
    Streamlit 1.38.0, Python 3.12