Fatal error: Uncaught Error: Class "Drupal\Core\Action\ActionBase" not found in /home/www/drupal8/test/core/lib/Drupal/Core/Field/FieldUpdateActionBase.php:28 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/lib/Drupal/Core/Field/FieldUpdateActionBase.php on line 28