put ownCloud in maintenance mode: edit /var/www/owncloud/config/config.php and change this line: 'maintenance' => false, to 'maintenance' => true, bash# cd /var/www/owncloud/data bash# sqlite3 owncloud.db sqlite> DELETE FROM oc_file_locks WHERE 1; sqlite> exit; then edit /var/www/owncloud/config/config.php and change this line: 'maintenance' => true, to 'maintenance' => false, https://central.owncloud.org/t/file-is-locked-how-to-unlock/985