Fatal error: Uncaught Error: Class "Drupal\Core\Ajax\BaseCommand" not found in /home/www/drupal8/test/core/modules/quickedit/src/Ajax/FieldFormValidationErrorsCommand.php:11 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/quickedit/src/Ajax/FieldFormValidationErrorsCommand.php on line 11