No supported hosts found for remediate
The operation is not supported on the selected Inventory objects.
Check the events for the objects selected for the operation.
This issue occurs because the admission control policy that is set is preventing vCenter Update Manager from remediating the host.
vCenter Server uses admission control to ensure that sufficient resources are available in a cluster to provide failover protection and to ensure that virtual machine resource reservations are respected. Admission control imposes constraints on resource usage and any action that would violate these constraints is not permitted. If an automated process needs to take actions, it may temporarily violate the failover constraints. For example, as part of an upgrade directed by VMware vCenter Update Manager.
After the ESX/ESXi host is successfully remediated, re-enable VMware HA on the cluster in the event of future host failovers.