Uncaught (in promise): timer after creating SweetAlert2 notification

Question

I am using SweetAlert2 messages for notification but when this message executed then it is showing error like this in console.

Uncaught (in promise): timer

here is my alert message

swal({
  text: "Your data is being saved",
  showConfirmButton: false,
  timer: 1000
}).then(function () {

})