When attempting an update on the Event object the API returns errors:
Error code = FIELD_INTEGRITY_EXCEPTION.
Error message = reassignDisallowed: Owner

I'm simply trying to update the OwnerId field on an Event object using the Java API.

I also get an error when I try to make this update via the Excel Connector, so it seems that there is a fundamental issue going on here. Furthermore, I did not get this error from the same code in the same circumstances before the new SFDC release that just launched.

Can anyone tell me why owner reassignment would be disallowed for an Event? The same owner id can be reassigned as owner of a contact record, so I know that there is nothing fundamental on the user record (like being inactive) preventing reassignment.

Thanks.