Warning: include(C:\xampp\htdocs\oa-OLD\vendor\yiisoft\yii2/di/Container.php): failed to open stream: Invalid argument in C:\xampp\htdocs\oa-OLD\vendor\yiisoft\yii2\BaseYii.php on line 292

Warning: include(): Failed opening 'C:\xampp\htdocs\oa-OLD\vendor\yiisoft\yii2/di/Container.php' for inclusion (include_path='C:\xampp\php\PEAR') in C:\xampp\htdocs\oa-OLD\vendor\yiisoft\yii2\BaseYii.php on line 292

Fatal error: Uncaught exception 'yii\base\UnknownClassException' with message 'Unable to find 'yii\di\Container' in file: C:\xampp\htdocs\oa-OLD\vendor\yiisoft\yii2/di/Container.php. Namespace missing?' in C:\xampp\htdocs\oa-OLD\vendor\yiisoft\yii2\BaseYii.php:295 Stack trace: #0 [internal function]: yii\BaseYii::autoload('yii\\di\\Containe...') #1 C:\xampp\htdocs\oa-OLD\vendor\yiisoft\yii2\Yii.php(27): spl_autoload_call('yii\\di\\Containe...') #2 C:\xampp\htdocs\oa-OLD\apps\web\index.php(6): require('C:\\xampp\\htdocs...') #3 {main} thrown in C:\xampp\htdocs\oa-OLD\vendor\yiisoft\yii2\BaseYii.php on line 295