EWS Managed API - Appointment creation with empty RequiredAttendees Problem

Hi,

I'm using the EWS Managed API.

I'm having trouble with appointment creation. My RequiredAttendees is an empty attendeeCcollection.

When I do a Save() on my appointment, i get the folowing exception :

The request failed schema validation: The element 'RequiredAttendees' in namespace 'http://schemas.microsoft.com/exchange/services/2006/types' has incomplete content. List of possible elements expected: 'Attendee' in namespace 'http://schemas.microsoft.com/exchange/services/2006/types'.

Can anyone tell me why please ?

Thanks in advance