Fatal error: Uncaught Error: Class "ilAbstractUsersGalleryUserCollectionSorter" not found in /var/www/html/ilias/components/ILIAS/User/classes/Gallery/class.ilUsersGalleryUserCollectionPublicNameSorter.php:20 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/User/classes/Gallery/class.ilUsersGalleryUserCollectionPublicNameSorter.php on line 20