diff --git a/server/app/common/server/UrlServer.php b/server/app/common/server/UrlServer.php
index 33d35db5..423a9988 100644
--- a/server/app/common/server/UrlServer.php
+++ b/server/app/common/server/UrlServer.php
@@ -48,7 +48,7 @@ class UrlServer
             $domain = request()->domain();
         } else {
             $config = ConfigServer::get('storage_engine', $engine);
-            $domain = $config['domain'];
+            $domain = $config['domain'] ?? '';
         }
         return self::format($domain, $uri);
     }