workspace_thread_assignee_invalid
HTTP 422§9.17 The customer team workspace on the phone (`/v1/mobile/workspace/*`, `/v1/mobile/voice/token`)
A conversation goes only to an active member of this company who can open it. reason: not_an_active_member (unknown, another company's, suspended or revoked) or cannot_see_conversation (a rep whose relationships do not include this customer). Nothing changed.
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/workspace_thread_assignee_invalid",
"title": "…",
"status": 422,
"detail": "…",
"instance": "/v1/…"
}