fix

backend/config/params.php

@@ -3,4 +3,6 @@ return [
     'adminEmail' => 'admin@example.com',
     'name' => 'Арт Проект',
     'user.passwordResetTokenExpire' => 3600,
+    'frontUrl' => 'http://task-on.com',
+    'backUrl' => 'http://taskon.task-on.com'
 ];

common/modules/bids/models/BidFile.php

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

frontend/config/params.php

@@ -2,4 +2,6 @@
 return [
     'adminEmail' => 'admin@example.com',
     'name' => 'Арт Проект',
+    'frontUrl' => 'http://task-on.com',
+    'backUrl' => 'http://taskon.task-on.com'
 ];