Fatal error: Uncaught Error: Class "Symfony\Component\Validator\Constraint" not found in /home/qcsvlel/www/core/modules/ckeditor5/src/Plugin/Validation/Constraint/ToolbarItemConstraint.php:20 Stack trace: #0 {main} thrown in /home/qcsvlel/www/core/modules/ckeditor5/src/Plugin/Validation/Constraint/ToolbarItemConstraint.php on line 20