Fatal error: Uncaught Error: Class "ilBlockGUI" not found in /var/www/html/ilias/components/ILIAS/Mail/classes/class.ilPDMailBlockGUI.php:30 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/Mail/classes/class.ilPDMailBlockGUI.php on line 30