fix

backend/config/main.php

@@ -130,6 +130,8 @@ return [
             'showScriptName' => false,
 			'enableStrictParsing' => true,
             'rules' => [
+				'bids/bod-admin/download/<file>'		=> 'bids/bod-admin/download',
+
 				'<module_id>/settings/manage'		=> 'settings/manage',
 				'<module_id>/settings/create'		=> 'settings/create',
 				'<module_id>/settings/update/<id>'	=> 'settings/update',

common/modules/bids/controllers/BidAdminController.php

@@ -108,6 +108,11 @@ class BidAdminController extends AdminController
         return $this->redirect(['/bids/bid-admin/manage']);
     }
 
+    public function actionDownload($file)
+    {
+        
+    }
+
     /**
      * Finds the Bid model based on its primary key value.
      * If the model is not found, a 404 HTTP exception will be thrown.

common/modules/bids/models/BidFile.php

@@ -81,11 +81,11 @@ class BidFile extends \common\components\ActiveRecordModel
 
     public function getUrl()
     {
-        return Yii::$app->params['backUrl'] . self::FILE_FOLDER . $this->filename;
+        return Yii::$app->params['backUrl'] . '/bids/bid-admin/download/' . $this->filename;
     }
 
     public static function path()
     {
-        return Yii::getAlias('@backend/web') . self::FILE_FOLDER;
+        return Yii::getAlias('@backend') . self::FILE_FOLDER;
     }
 }