I have exact same issue.
Additionally I cannot run "Web Operator" due to error: "The webview 'weboperator' is not published."
I've followed this https://communities.vmware.com/message/2327285#2327285 but did not help.
Any idea if the issues are related and how to resolve it ?
Judging by the screenshots, you try to enter the vCenter Server IP when trying to register the vco.
You should use the vCO server IP.
I've tried vCO IP and FQDN, none of it works ...
Any clues in vSphere Web Client log files?
Welcome to the world of VMware's completely horrible incomplete documentation! Actually it might be documented sufficiently somewhere but I cant sent you an RTFM to it off the top of my head. Anyway I can forward you this excellent post on how to set this up. vCenter Server & vCenter Orchestrator 5.1 integration tips . The key step you are likely missing is getting the SSO security group all setup correctly. The example shows using SSO entities but you can also use AD entities you just have to make sure your vRO is configured to use SSO. Anyway walk through this step by step and all will be good. You can ignore any vRO appliance refrences as this is valid for both the appliance and they windows version of vRO.