Fatal error: Uncaught Error: Class "Drupal\Core\Ajax\AjaxResponse" not found in /home/www/drupal8/test/core/modules/views/src/Ajax/ViewAjaxResponse.php:13 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/views/src/Ajax/ViewAjaxResponse.php on line 13