Fatal error: Uncaught Error: Interface "Drupal\Core\Entity\EntityHandlerInterface" not found in /home/www/drupal8/test/modules/webform/src/WebformSubmissionViewBuilderInterface.php:11 Stack trace: #0 {main} thrown in /home/www/drupal8/test/modules/webform/src/WebformSubmissionViewBuilderInterface.php on line 11