I recently upgraded vCenter and ESXI 5.5 to 6.5 and upgrade was successful. I deployed some new VMs on upgraded ESXI hosts but when I try to power on I am getting error "The host is reporting errors in its attempts to provide vSphere HA support.”"
When I turned off the HA on cluster and try to power on new VM then I get error “The available Memory resources in the parent resource pool are insufficient for the operation.”
The odd thing was, there were no resource pools that had been setup. Nothing was reserved for any VM.