Hi @FREDDIE2020
This is as designed, Alerts in ERROR state are not available to be acknowledged.
If you don’t want to receive notification when error occurs in the monitor, you could add && ctx.error == null to the alert trigger conditions. (Kibana Alerting - Randomly Triggering No Data Returned - #11 by dooleyb1)
You could open an issue in GitHub (Issues · opendistro-for-elasticsearch/alerting · GitHub) if you have ideas to change this alert behavior.
Tianli