Fatal error: Uncaught Error: Class 'Drupal\Core\Entity\EntityConfirmFormBase' not found in /var/www/html/tmp/contrib/cer/src/Form/CorrespondingReferenceDeleteForm.php:12 Stack trace: #0 {main} thrown in /var/www/html/tmp/contrib/cer/src/Form/CorrespondingReferenceDeleteForm.php on line 12