no_ballot
409 · Conflicts with the current stateWhat happened
You asked to show your pick on a message, and there is no pick to show — either you have not voted in this session, or this deployment cannot check.
What to do
Vote first, then send it again with the marker. The message was not posted: a message that went out without the side you asked for would be worse than none.
Is retrying worth it
No. Repeating the identical request will fail identically. Something has to change first, and the line above says what.
Reading the response
Errors are RFC 9457 problem details. Switch on code, which is stable, and never on title, which is written for a person and may be reworded or translated. detail carries the specifics of this occurrence, and meta carries whatever the client needs to render the right state instead of a dead end.
Every response also carries an X-Request-Id header. Quote it if you report something — it is what lets us find the exact request.