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