Fatal error: Uncaught Error: Class 'Composer\Installer\PackageEvent' not found in /home/clienti2020/public_html/novaballet.it/vendor/composer/composer/src/Composer/Script/PackageEvent.php:22 Stack trace: #0 {main} thrown in /home/clienti2020/public_html/novaballet.it/vendor/composer/composer/src/Composer/Script/PackageEvent.php on line 22