Fatal error: Uncaught Error: Class "Composer\Installer\MetapackageInstaller" not found in /var/www/html/immo/vendor/symfony/flex/src/SymfonyPackInstaller.php:16 Stack trace: #0 {main} thrown in /var/www/html/immo/vendor/symfony/flex/src/SymfonyPackInstaller.php on line 16