Fatal error: Uncaught Error: Class "Symfony\Component\Serializer\Exception\NotEncodableValueException" not found in D:\Webserver\Apache24\htdocs\testephp\signxml\vendor\symfony\serializer\Exception\UnsupportedFormatException.php:17 Stack trace: #0 {main} thrown in D:\Webserver\Apache24\htdocs\testephp\signxml\vendor\symfony\serializer\Exception\UnsupportedFormatException.php on line 17