Fatal error: Uncaught Error: Class "Drupal\webform\Element\WebformExcludedBase" not found in /home/www/drupal8/test/modules/webform/src/Element/WebformExcludedColumns.php:12 Stack trace: #0 {main} thrown in /home/www/drupal8/test/modules/webform/src/Element/WebformExcludedColumns.php on line 12