Oops, I wanted to move the local cluster from fleet-local to fleet-default (using the change workspace button) to try deploying things to all clusters and it just disappeared. Can't see the cluster in cluster management any more. How can I restore/recreate it? The

spec.fleetWorkspaceName: fleet-default

shows under the corresponding management.cattle.io/v3 resource

You could restore Rancher from backup https://rancher.com/docs/rancher/v2.6/en/backups/