I migrated all except comments without big problems. But when I try "drush migrate-import d6_comment"
I get error
Argument 1 passed to Drupal\forum\ForumIndexStorage::updateIndex() must implement interface Drupal\node\NodeInterface, null given, called in [error]
/Users/Home/Sites/my_new_site/core/modules/forum/forum.module on line 261 and defined ForumIndexStorage.php:97
Drush command terminated abnormally due to an unrecoverable error.