Fatal error: Uncaught Error: Interface "Drupal\Component\Plugin\PluginManagerInterface" not found in /home/www/drupal8/test/core/modules/migrate/src/Plugin/MigratePluginManagerInterface.php:7 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/migrate/src/Plugin/MigratePluginManagerInterface.php on line 7