Fatal error: Uncaught Error: Class "OCP\AppFramework\Db\QBMapper" not found in /home/tremblinlu/MyNextCloud/nextcloud/lib/private/Updater/ChangesMapper.php:35 Stack trace: #0 {main} thrown in /home/tremblinlu/MyNextCloud/nextcloud/lib/private/Updater/ChangesMapper.php on line 35