Error loading dependencies/layout or Server Error 500

Hello, I have a small application. The app read data from Firestore of Google and it is deployed in the App Engine of Google.
Locally runned app works fine, but when i deploy app to App Engine and I try connect to the web page I can see some errors but just sometimes.

In App Engine I use standard mode, I just rewrited example “Hello World” main.py with my app and I added some packages to requirements.txt.

When I run app in flex mode of App Engine, looks that it works fine.

Can someone help me?

If You’re Trying to Load a Page with a 500 Internal Server Error:

  1. Refresh the page.
    This might seem obvious, but if it’s a temporary loading issue, you might find success if you refresh the page. Before trying anything else in this list, reload the page and see what happens.

  2. Come back later.
    Since the error is on the server side, I’m willing to bet the website owners are working as quickly as possible to resolve the issue. Give it a few minutes or up to an hour or so, and then reload the URL and see if the development team has fixed the issue.

Regards,
Rachel Gomez