Cause
The preview_digest or digest is missing, does not match the content, identity and revision sent, or the effects changed since the preview. With affected highlights or campaigns the preview_digest is mandatory. A test digest is not valid in production.
What to do
Repeat the preview and use its digest. If there are critical or confirmation-required effects, also send confirm_linked_highlight_effects: true.
application/problem+json
{
"type": "https://masnet.com/developers/errors/preview_stale",
"title": "Stale preview",
"status": 409,
"detail": "...",
"code": "preview_stale",
"correlation_id": "..."
}