Fatal error: Uncaught Error: Class "Drupal\views\Plugin\views\argument_default\ArgumentDefaultPluginBase" not found in /home/www/drupal8/test/core/modules/user/src/Plugin/views/argument_default/CurrentUser.php:19 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/user/src/Plugin/views/argument_default/CurrentUser.php on line 19