Fatal error: Uncaught Error: Class "Drupal\block\Plugin\migrate\source\Block" not found in /home/www/drupal8/test/core/modules/block/src/Plugin/migrate/source/d6/BlockTranslation.php:17 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/block/src/Plugin/migrate/source/d6/BlockTranslation.php on line 17