I do have exactly the same issue, I also checked the log /var/lod/vmware/vsphere-clients/logs/vsphere_client_virgo.log but did not find anything useful.
Did someone already solve this issue?
I just double checked that and the service is running and healthy. Also in the Summary tab de Health Status is working.
Did you manage to get this resolved? Getting the same issue after updating the web certificate.
When you monitor Windows vCenter Server health, an error message appears
Health service is not available for Windows vCenter Server. If you select the vCenter Server, and click Monitor > Health, an error message appears:
Unable to query vSAN health information. Check vSphere Client logs for details.
This problem can occur after you upgrade the Windows vCenter Server from release 6.0 Update 1 or 6.0 Update 2 to release 6.7. You can ignore this message.
Workaround: None. Users can access vSAN health information through the vCenter Server Appliance.