epoch_mismatch· code· HTTP 409· scope bothAn encrypted authoring request references an epoch, group_state_ref or key_access_revision that differs from the ready current MLS group. HTTP 409. After verifying and acquiring current local MLS state, the sender re-encrypts into a new request; an exact retry of the old request does not re-encrypt. If the current scope itself awaits a winning Commit, failed_precondition with epoch_update_required takes precedence. Historical accepted Event replay and peer committed replication use their accepted historical binding.