missing_header

A required header is missing.

HTTP 400.

Likely causes:

• X-Actor, X-Reason or Idempotency-Key is missing on a mutating call.
• X-Actor, X-Reason or Idempotency-Key is missing when changing the API version pin.

What to do: Send the headers named in the message.

Retry: No. The same request gets the same answer; change something first.

Listed under Requests and validation in Errors. Send the error’s requestId to support and we can find the request.