Cause
The subjects references could not be resolved at this time. The request had no effect and the response includes Retry-After: 5.
What to do
Retry after the delay with the same Idempotency-Key.
application/problem+json
{
"type": "https://masnet.com/developers/errors/subjects_unavailable",
"title": "References unavailable",
"status": 503,
"detail": "...",
"code": "subjects_unavailable",
"correlation_id": "..."
}