Fatal error: Uncaught Error: Class "Drupal\Component\Serialization\Yaml" not found in /home/qcsvlel/www/core/modules/file/tests/fixtures/update/file_post_update_playsinline-3046152.php:15 Stack trace: #0 {main} thrown in /home/qcsvlel/www/core/modules/file/tests/fixtures/update/file_post_update_playsinline-3046152.php on line 15