Fatal error: Uncaught Error: Class "Composer\Installer\LibraryInstaller" not found in /srv/www/cntait.org/www/site.tree/public/wp-content/plugins/wp-nested-pages/vendor/composer/installers/src/Composer/Installers/Installer.php:8 Stack trace: #0 {main} thrown in /srv/www/cntait.org/www/site.tree/public/wp-content/plugins/wp-nested-pages/vendor/composer/installers/src/Composer/Installers/Installer.php on line 8