White screen of the main page (Symfony framework) and no errors in the logs. What could be wrong?

Question

symfony

I migrated the site to the new Hetzner server, everything was successful and without errors.
The strange thing is that the main page of the site is just a white screen, other pages work fine.
Debbager shows empty html. There are no errors in the logs. Not sure where to look to fix it.
Tell me, please, where to look?

Answer 1

Is the var folder writable?