No occ file in var/www/owncloud folder

Hi all

After an update of apache2, i'm not able anymore to log into my owncloud through the web access. I receive an error 404.
I would like to repair owncloud through the occ command but I do not have any occ file in the folder /var/www/owncloud anymore.

Would one of you have an idea how to bring it back by any chance?

Thanks

Looks like the same you have already posted in https://central.owncloud.org/t/404-error-after-apache-update/9583 ?

Definitively the same issue. I tried to explain it in a shorter way, hopping to attract more answers as I'm quite desperate.