Fatal error: Uncaught Error: Class 'Composer\Installer\LibraryInstaller' not found in /data0/wwwroot/online.chinesephoto.cn/vendor/topthink/think-installer/src/ThinkExtend.php:18 Stack trace: #0 {main} thrown in /data0/wwwroot/online.chinesephoto.cn/vendor/topthink/think-installer/src/ThinkExtend.php on line 18