Fatal error: Uncaught Error: Class 'Drupal\Composer\Plugin\Scaffold\Operations\AbstractOperation' not found in /home/devmecseminars/public_html/mec/vendor/drupal/core-composer-scaffold/Operations/AppendOp.php:14 Stack trace: #0 {main} thrown in /home/devmecseminars/public_html/mec/vendor/drupal/core-composer-scaffold/Operations/AppendOp.php on line 14