collection_method_change_conflict
Another capacity purchase, upgrade, or collection-method change owns this subscription; the request key names a different target; or the saved source no longer matches. Recover the existing operation before starting a new change. No new provider write is dispatched by the refused request.
Problem shape
Every non-2xx response is an RFC 9457 application/problem+json body. The type URI below is stable and machine-matchable, so branch on the final path segment (the code) and treat the status as redundant confirmation. See the error-handling guide.
{
"type": "https://docs.vocapable.com/errors/collection_method_change_conflict",
"title": "…",
"status": 409,
"detail": "…",
"instance": "/v1/…"
}