Fatal error: Uncaught Error: Class "Aws\Api\Serializer\RestSerializer" not found in D:\www\cmd\cmd_api\vendor\aws\aws-sdk-php\src\Api\Serializer\RestXmlSerializer.php:10 Stack trace: #0 {main} thrown in D:\www\cmd\cmd_api\vendor\aws\aws-sdk-php\src\Api\Serializer\RestXmlSerializer.php on line 10