Fatal error: Uncaught Error: Class "Composer\Installer\LibraryInstaller" not found in /home/telefonai/public_html/test.telefonai.eu/vendor/craftcms/plugin-installer/src/Installer.php:21 Stack trace: #0 {main} thrown in /home/telefonai/public_html/test.telefonai.eu/vendor/craftcms/plugin-installer/src/Installer.php on line 21