Fatal error: Uncaught Error: Class "ilPageObjectGUI" not found in /var/www/html/ilias/components/ILIAS/LearningSequence/classes/PageEditor/class.ilLearningSequencePageObjectGUI.php:25 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/LearningSequence/classes/PageEditor/class.ilLearningSequencePageObjectGUI.php on line 25