Fatal error: Uncaught Error: Class "Drupal\Core\Menu\MenuLinkTree" not found in /home/www/drupal8/test/core/modules/toolbar/src/Menu/ToolbarMenuLinkTree.php:10 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/toolbar/src/Menu/ToolbarMenuLinkTree.php on line 10