Fatal error: Uncaught Error: Class "Symfony\Component\DependencyInjection\ServiceLocator" not found in C:\Apache24\htdocs\cms_upgrade\vendor\symfony\dependency-injection\Argument\ServiceLocator.php:21 Stack trace: #0 {main} thrown in C:\Apache24\htdocs\cms_upgrade\vendor\symfony\dependency-injection\Argument\ServiceLocator.php on line 21