Fatal error: Uncaught Error: Interface "Symfony\Component\EventDispatcher\EventSubscriberInterface" not found in /home/www/drupal8/test/core/modules/migrate/src/Plugin/PluginEventSubscriber.php:15 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/migrate/src/Plugin/PluginEventSubscriber.php on line 15