Fatal error: Uncaught Error: Class "Drupal\config_translation\FormElement\FormElementBase" not found in /home/www/drupal8/test/core/modules/config_translation/src/FormElement/TextFormat.php:10
Stack trace:
#0 {main}
thrown in /home/www/drupal8/test/core/modules/config_translation/src/FormElement/TextFormat.php on line 10