Fatal error: Uncaught Error: Class "Kirby\ComposerInstaller\Installer" not found in /home/tusaisqu/new/vendor_old/getkirby/composer-installer/src/ComposerInstaller/CmsInstaller.php:16 Stack trace: #0 {main} thrown in /home/tusaisqu/new/vendor_old/getkirby/composer-installer/src/ComposerInstaller/CmsInstaller.php on line 16