organization_registration_challenge_invalid· code· HTTP 400· scope endpointThe referenced organization registration challenge is unknown, expired, already consumed without an exact successful-replay ledger match, or its purpose / audience / origin / trust_domain / local_admin_subject / requested_scopes binding does not match the submitted request. On first success the registry atomically records (challenge_id, canonical_request_digest, outcome): a byte-identical retry returns that outcome, while the same challenge with a different digest fails here rather than authorising a second intent.