This message failed to be delivered to the user because it was sent outside the messaging channel's allowed conversation window. For WhatsApp messages initiated by the business, you must use a pre-defined template.
If the message was created with Content API or Content Editor it may be one of the following 3 issues:
The customer has not included a messaging service SID
The customer is still using "body" instead of "Content SID" and "Content Variables"
The customer is using content type that is not supported for business initiated conversations, e.g. listpicker or location
For Facebook Messenger messages initiated by the business, only publishers registered with the Facebook News Page Index (NPI) are allowed to send notification messages outside the 24-hour window.