Fatal error: Uncaught Error: Class "Drupal\Core\Controller\ControllerBase" not found in /home/www/drupal8/test/modules/admin_toolbar/admin_toolbar_tools/src/Controller/ToolbarController.php:24 Stack trace: #0 {main} thrown in /home/www/drupal8/test/modules/admin_toolbar/admin_toolbar_tools/src/Controller/ToolbarController.php on line 24