Fatal error: Uncaught Error: Class "ilAbstractUsersGalleryCollectionProvider" not found in /var/www/html/ilias/components/ILIAS/User/classes/Gallery/class.ilUsersGalleryParticipants.php:24 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/User/classes/Gallery/class.ilUsersGalleryParticipants.php on line 24