The Campaign Cannot be Scheduled

[Navani-cpu]

any one can please help for this , I get following response

{
"type": "https://mailchimp.com/developer/marketing/docs/errors/",
"title": "Bad Request",
"status": 400,
"detail": "This campaign cannot be scheduled: .",
"instance": "74b79ed7-5a20-147d-af0c-01ff2db59ecd"
}