Fatal error: Uncaught Error: Class 'Composer\Installer\LibraryInstaller' not found in C:\xampp\htdocs\web\yii\basic\vendor\yiisoft\yii2-composer\Installer.php:21 Stack trace: #0 {main} thrown in C:\xampp\htdocs\web\yii\basic\vendor\yiisoft\yii2-composer\Installer.php on line 21