pi@EvelRusServer:/var/www/html/nextcloud$ sudo -u www-data php occ db:add-missing-indices
Your data directory is readable by other users
Please change the permissions to 0770 so that the directory cannot be listed by other users.

An unhandled exception has been thrown:
Exception: Environment not properly prepared. in /var/www/html/nextcloud/lib/private/Console/Application.php:167
Stack trace:
#0 /var/www/html/nextcloud/console.php(98): OC\Console\Application->loadCommands(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#1 /var/www/html/nextcloud/occ(11): require_once('/var/www/html/n...')
#2 {main}pi@EvelRusServer:/var/www/html/nextcloud$