Error after successfyllu deploying and running the app. No module named 'st_paywall'

Hi, I am deploying my app on streamlit cloud (https://textgrader-wernicke.streamlit.app/)
and encountering the following error message:
" ```
2023-12-17 12:31:45.753 Uncaught app exception

Traceback (most recent call last):

File “/home/adminuser/venv/lib/python3.9/site-packages/streamlit/runtime/scriptrunner/script_runner.py”, line 534, in _run_script

    exec(code, module.__dict__)

File “/mount/src/wernicke_text-scrutinizer-ai/Home.py”, line 2, in

    from st_paywall import add_auth

ModuleNotFoundError: No module named ‘st_paywall’

2023-12-17 12:31:45.966 503 GET /script-health-check (10.13.112.174) 233.03ms
```" (This just keeps repeating)
although the app was successfully deployed and running with no problem beforehand.
I encounter this error time to time even when no changes were made to the app.

This has occurred several times and I usually solve this by rebooting the app. (which takes over night.)
I would love to know
- why the error appears
- why it still is successfully deployed after taking so long 
- how I can make sure it does not happen again.

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The link to the app's GitHub repository: https://github.com/bigkaiyoh/Wernicke_Text-Scrutinizer-AI
Streamlit version: Streamlit, version 1.29.0
Python version: Python 3.11.3

Same here

ModuleNotFoundError: No module named 'st_paywall'

But my App was running successfully for weeks with that module.
I now think that Streamlit is not the right choice if you want to create a permanently functional and professional app. Things that have worked all the time without any problems suddenly stop working “overnight”. And no chance of finding a quick solution to the problems. Yes, it’s free - even the hosting - but what good is that if it doesn’t work reliably?