Fatal error: Uncaught Error: Class "Drupal\migrate\Plugin\MigrationPluginManager" not found in /home/www/drupal8/test/core/modules/migrate_drupal/src/MigrationPluginManager.php:26 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/migrate_drupal/src/MigrationPluginManager.php on line 26