When creating a Webinar and adding an Event Speaker, the Webinar_Panelist_ID_vod__c and Webinar_Panelist_URL_vod__c fields remain empty.
The Account which is added as an Event Speaker to the Webinar does not have a valid email address in the PersonEmail field on the Account record.
A valid email address in the PersonEmail field on the Account record must be set to the Account which is added to the Webinar as an Event Speaker. In case the Account is already added to the Webinar, it must be removed and re-added in order to make the Webinar_Panelist_ID_vod__c and Webinar_Panelist_URL_vod__c fields populated.
The Event Speaker email address is required by the server. If a speaker does not have an email address on file, no request is sent to the server. Thus, the Webinar field is not populated.