The above has worked on all previous instances on docker compose, sorry it seems not to work on your bare metal and for NextCloud v20.
With some help of a friend we have figured out that you need to turn off the maintenance mode in ~/config.php manually. It should reside in /var/www/html/config/config.php
Open with your favourite text editor.
You will find a line:
’maintenance’ => true,
this needs to be changed to
’maintenance’ => false,
Save and exit.
You can probably do it with a command like this, too:
sudo -u www-data php /var/www/nextcloud/occ maintenance:mode --off
But I suggest to change it manually.
For reference to those running NextCloud in a docker image (our setup is using nextcloud:fpm-alpine docker container) here it worked to do:
docker exec -it -u www-data YOUR_DOCKER-CONTAINER_ID sh -c ‘php ./occ maintenance:mode --off’
Hopefully this will also work on your end!
Final note: your config.php looks corrupted as the line ‘maintenance’ shows up twice. Maybe a clean install will help a lot and then move your backed up data in again.