Fatal error: Uncaught Error: Class "Drupal\ckeditor5\Plugin\CKEditor5PluginDefault" not found in /home/qcsvlel/www/core/modules/ckeditor5/src/Plugin/CKEditor5Plugin/Heading.php:21 Stack trace: #0 {main} thrown in /home/qcsvlel/www/core/modules/ckeditor5/src/Plugin/CKEditor5Plugin/Heading.php on line 21