Hardware: Dell R720 YunoHost version: Powered by YunoHost 4.15 (stable). I have access to my server : SSH, webadmin, direct access Are you in a special context or did you perform some particular tweaking on your YunoHost instance ? : not really. I have a RAID server.
it’s a lot more serious than I realized, almost none of the apps work now, including nextcloud. the error seems to be related to a directory not existing for backdrop uninstall but I don’t know how to delete a directory that doesn’t exist
It looks like the pool conf has not been deleted?
Can you check that it is still there with ls /etc/php/7.3/fpm/pool.d/backdrop.conf ?
If it does not return an error: rm /etc/php/7.3/fpm/pool.d/backdrop.conf and reload the service again.