Heroku throws 500 error without any response about error – with [Symfony]

  heroku, php, symfony

Recently i decided to host my project on Heroku platform. It uses React and Symfony technology. I properly installed CLI, created app and pushed my whole project. After successfull build i open an app and this error appears:

The server returned a "500 Internal Server Error".

I tried to check my logs and only thing i found is this:

Oct 12 07:32:39 pokedex-advanced-app heroku/router at=info method=GET path="/" host=pokedex-advanced-app.herokuapp.com request_id=cc14efd0-2328-4440-923e-76245aca818c fwd="" dyno=web.1 connect=0ms service=15ms status=500 bytes=1178 protocol=http
Oct 12 07:32:40 pokedex-advanced-app app/web.1 - - [12/Oct/2020:14:32:39 +0000] "GET / HTTP/1.1" 500 831 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.75 Safari/537.36

Procfile is conficurated properly and database is also working. Any ideas why it happens and how to fix this?

Source: Symfony Questions