Error 16028
Product: Programmable Voice
ERROR - 16028
Participant to be whispered is not present in the conference
The participant to be whispered is not present in the conference, so the coach to the participant cannot be added to the conference.
Possible Causes
This may because the specified participant is not yet connected to the conference or no longer connected to the conference.
Possible Solutions
Validate that this call is connecting to the correct conference and the call SID specified is also in the conference.