When we remove the faulty node on the cluster or on a good node, an error occurs: Error removing the node from cluster，What is the cause of this?
【The faulty node has been taken off the shelf and is not in the cluster network】
Thank you for contacting the Sophos Community.
Try rebooting the appliance, and see if the cluster has disappeared, if not, open a case with Support, so they can investigate in the backend.
The customer is currently using an ES device and cannot reboot. I have opened a case for tac to support, THX.