Fatal error: Uncaught Error: Class 'Composer\Installer\LibraryInstaller' not found in /var/www/vhosts/www.thomas-bartholomaeus.de/content/neoscms/Packages/Libraries/neos/composer-plugin/Classes/Installer.php:12 Stack trace: #0 {main} thrown in /var/www/vhosts/www.thomas-bartholomaeus.de/content/neoscms/Packages/Libraries/neos/composer-plugin/Classes/Installer.php on line 12