diff --git a/fplus-http-server/src/router/application.rs b/fplus-http-server/src/router/application.rs
index c741034..5774777 100644
--- a/fplus-http-server/src/router/application.rs
+++ b/fplus-http-server/src/router/application.rs
@@ -242,7 +242,7 @@ pub async fn approve(
         .await
     {
         Ok(_) => HttpResponse::Ok().body(serde_json::to_string_pretty("Success").unwrap()),
-        Err(e) => HttpResponse::BadRequest().body(e),
+        Err(e) => HttpResponse::BadRequest().body(e.to_string()),
     }
 }