How to update conference details using UCMA 3.0?

I've created a conference using UCMA 3.0,

Now what I want to do is to modify conference details that I've created previously.

I've tried

 private void ModifyConference(string confId)
        {
                // The base conference settings object, used to set the policies for the conference.
                ConferenceScheduleInformation conferenceScheduleInformation = new ConferenceScheduleInformation();
                // An open meeting (participants can join who are not on the list), 
                // but requiring authentication (no anonymous users allowed.)

                conferenceScheduleInformation.ConferenceId = confId;
                _callerEndpoint.ConferenceServices.BeginUpdateConference(conferenceScheduleInformation, EndUpdateConference, _callerEndpoint.ConferenceServices);

                _waitForConferenceUpdating.WaitOne();
            }
        }

private void EndUpdateConference(IAsyncResult ar)
        {
            ConferenceServices confSession = ar.AsyncState as ConferenceServices;
            try
            {
                confSession.EndUpdateConference(ar);
            }
            catch (Exception ex)
            {

            }
            _waitForConferenceUpdating.Set();
        }

When I execute this code it is throwing an Exception

{"The request failed with reason: invalidVersion."}