Today i found out the hard way that apparently since vROPS 6.6 it is NOT possible to view vROPS health bars in the 6.5U1 web client. (I recently upgraded from windows vCenter 5.5 to 6.5U1 appliance)
Before i knew about this i was following several KBs where the solution for *enabling* vROP 6.x health bars in vCenter web client is to *remove* the "com-vmware.vcops" extension under https://vcenter.fqdn/mob (note do NOT do this)
BUT if you do this you will apparently BREAK hourly reporting engine in UM. So i now get (every hour) alerts from both UM 3.5 and UM 3.6
"vRealize Operations Manager: Missing vCenter extension"...
So whatevery you do *DO NOT* attempt to "repair" the vROPS missing health badges in vCenter web client if you are running vROPS 6.6 as per KB: https://kb.vmware.com/kb/2146360 you risk end up with f*** up UM... It seems as if the extension folder is present on the vCenter server everything is nice and dandy, but as soon as you delete the 6.5 (in my case) extension folder on the vCenter server applaiance shit will hit the fan...
I will now have to install a third UM 3.6.0.1 instance or perhaps try to upgrade the broken 3.6 and see it if repairs this extension error. Although i doubt that since the "error" is on vCenter server.
I have removed/deleted my vCenter server, rebooted all UM appliances and also stopped and started the vROPS 6.6 collector but it has not helped.
From UM 3.6 Release Notes: VMware vCloud Usage Meter 3.6 Release Notes
- vCloud Usage Meter cannot discover vRealize Operations Manager 6.6 vRealize Operations Manager 6.6 does not include a vSphere Web Client plugin. As a result, vRealize Operations Manager does not register itself as a plugin to the associated vCenter Server and is not present in the extension manager of the vCenter Server. When you add a vCenter Server to be metered, vCloud Usage Meter is not able to discover the associated vRealize Operations Manager.Workaround: None.
- vRealize Operations Manager collections fail Workaround: When adding a new vRealize Operations Manager, accept the certificate before providing the required credentials. (i have not tried nor do i want to install a NEW vROPS server...!)
The vRealize Operations Manager NGC plugin for the vSphere Web Client has been removed in vRealize Operations Manager 6.6. please see: https://docs.vmware.com/en/vRealize-Operations-Manager/6.6/rn/vrops-66-release-notes.html
I have tried KB 2150394 but script failed at row 13)
Not very happy right now! 
I would also like to point out the it is a fully supported path, yet it is not working...
VMware Product Interoperability Matrices
Hi,
It seems that Usage Meter 3.6/3.6.0.1 cannot meter vRealize Operations Manager (vROps) 6.6 and it meters vROPS 6.6.1 - > VMware Product Interoperability Matrices
For more interoperability information about Usage Meter, see Interoperability Pages for vCloud Usage Meter 3.6.
Recommended to upgrade to vROps 6.6.1. Hope this helps.
Best Regards,
Vinayaga.