Trying to add an event to Outlook calendar through my event registration app using asp.net/C#. Getting call was rejected by callee error when trying to initialize (line 1). How do I overcome this issue?

Error:
"Retrieving the COM class factory for component with CLSID {0006F03A-0000-0000-C000-000000000046} failed due to the following error: 80010001 Call was rejected by callee. (Exception from HRESULT: 0x80010001 (RPC\_E\_CALL\_REJECTED))."

```
Outlook.Application outlookapp = new Outlook.Application();
Outlook.AppointmentItem appt = outlookapp.CreateItem(Outlook.OlItemType.olAppointmentItem) as Outlook.AppointmentItem;
appt.Subject = er.Event.Name;
appt.MeetingStatus = Outlook.OlMeetingStatus.olMeeting;
appt.Location = er.Event.LocationName;
appt.Start = er.Event.StartTime;
appt.End = er.Event.EndTime;
appt.Recipients.ResolveAll();
appt.Display(false);
appt.Save();

```