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