Fatal error: Uncaught Error: Class "Drupal\Core\Form\ConfirmFormBase" not found in /home/qcsvlel/www/core/lib/Drupal/Core/Entity/Form/RevisionRevertForm.php:28 Stack trace: #0 {main} thrown in /home/qcsvlel/www/core/lib/Drupal/Core/Entity/Form/RevisionRevertForm.php on line 28