topic_locked

This kind of email can not be turned off.

HTTP 400.

Likely cause: Turning off the billing or security topic in the email notification settings.

What to do: Leave it on. Billing and security emails are always sent.

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

Listed under Sign-in and organisations in Errors. Send the error’s requestId to support and we can find the request.