Xrm.Page.data.save().then is not working in CRM 2016 Online environment

Hi,

I am getting problem while using Save().Then function in MS CRM Dynamics 2016 Version.

 Xrm.Page.data.save().then(thenSuccessFunction, thenErrorFunction);

issue:-

Goes into Errorcallback ..message displayed is as below

errorCode = Xrm.SaveErrorResponse {errorCode: -1, message: "serviceIsBusy", debugMessage: null}.

Appreciate your help.

Note:

1. Form rendering engine is enabled.

2. Form is Quote entity main form.