Fatal error: Uncaught Error: Class "OpenCloud\ObjectStore\Upload\AbstractTransfer" not found in /app/vendor/rackspace/php-opencloud/lib/OpenCloud/ObjectStore/Upload/ConcurrentTransfer.php:30 Stack trace: #0 {main} thrown in /app/vendor/rackspace/php-opencloud/lib/OpenCloud/ObjectStore/Upload/ConcurrentTransfer.php on line 30