Fatal error: Uncaught Error: Class 'Drupal\Core\Entity\Sql\SqlContentEntityStorageSchema' not found in /var/www/html/tmp/contrib/flag/src/Entity/Storage/FlaggingStorageSchema.php:11 Stack trace: #0 {main} thrown in /var/www/html/tmp/contrib/flag/src/Entity/Storage/FlaggingStorageSchema.php on line 11