voicemail_drop_policy_invalid
The campaign's stored voicemail_drop document cannot be read as a policy, so launch cannot tell whether this program leaves messages. Refused rather than defaulted to "off": a hand-edited row must not silently disarm a gate (ADR-0023).
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/voicemail_drop_policy_invalid",
"title": "…",
"status": 409,
"detail": "…",
"instance": "/v1/…"
}