fix(ui): catch 5xx errors (#1788)

* fix(ui): xray check for data load

* fix(ui): api client catch errors

frontend/app/api_client.ts

@@ -159,6 +159,8 @@ export default class APIClient {
       } else {
         return Promise.reject({ message: `! ${this.init.method} error on ${path}; ${response.status}`, response });
       }
+    }).catch((error) => {
+      return Promise.reject({ message: `! ${this.init.method} error on ${path};` });
     });
   }