diff --git a/protected/humhub/modules/file/converter/BaseConverter.php b/protected/humhub/modules/file/converter/BaseConverter.php
index 6dab8de293..02d1e8e8a6 100644
--- a/protected/humhub/modules/file/converter/BaseConverter.php
+++ b/protected/humhub/modules/file/converter/BaseConverter.php
@@ -61,7 +61,7 @@ abstract class BaseConverter extends \yii\base\Object
      */
     public function getUrl()
     {
-        return $this->file->getUrl($this->getFileName());
+        return $this->file == null ? '' : $this->file->getUrl($this->getFileName());
     }
 
     /**