Cause
The policy or mapping of the source changed since the review; a new one is needed.
What to do
Validate the operation again.
application/problem+json
{
"type": "https://masnet.com/developers/errors/source_policy_changed",
"title": "Source policy changed",
"status": 409,
"detail": "...",
"code": "source_policy_changed",
"correlation_id": "..."
}