Fatal error: Uncaught Error: Class "Symfony\Component\DependencyInjection\Dumper\Dumper" not found in C:\Apache24\htdocs\cms_upgrade\vendor\symfony\dependency-injection\Dumper\XmlDumper.php:32 Stack trace: #0 {main} thrown in C:\Apache24\htdocs\cms_upgrade\vendor\symfony\dependency-injection\Dumper\XmlDumper.php on line 32