Nextcloud update using cli only
Nextcloud can be updated using the Nextcloud command line interface only. Even your enabled apps will be updated as far as they are available on the Nextcloud app store. But first backup your Nextcloud system (database and data).
sudo -s cd /var/www sudo -u www-data php nextcloud/updater/updater.phar
Press y to start updating your Nextcloud
Now the code was updated and the occ upgrade should be performed. Press y to continue.
Press n to disable Nextclouds maintenance mode and the update has ben finished already.
You are on the latest Nextcloud release – can be verifed by
sudo -u www-data php /var/www/nextcloud/occ status sudo -u www-data php /var/www/nextcloud/occ -V
Enjoy your personal data in your secured and hardened Nextcloud-Server!
Don’t forget to backup your Nextcloud
Find more instructions here: Nextcloud Backup and Restore