Fatal error: Uncaught Error: Interface "ilSkillTreeRepository" not found in /var/www/html/ilias/components/ILIAS/Skill/Tree/class.ilSkillTreeDBRepository.php:24 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/Skill/Tree/class.ilSkillTreeDBRepository.php on line 24