Fatal error: Uncaught Error: Class "Drupal\Core\Render\Annotation\RenderElement" not found in /home/www/drupal8/test/core/lib/Drupal/Core/Render/Annotation/FormElement.php:25 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/lib/Drupal/Core/Render/Annotation/FormElement.php on line 25