Cause
No person in the audience can respond today, because of permissions or because they are disabled.
What to do
Review the audience of the campaign.
application/problem+json
{
"type": "https://masnet.com/developers/errors/empty_cohort",
"title": "Empty cohort",
"status": 422,
"detail": "...",
"code": "empty_cohort",
"correlation_id": "..."
}