I keep forgetting this to be a problem so might as well write it down for myself and anyone else stumbling upon this.
When using vRO, in my case 7.5 or 7.6, you might get a problem where you are unable to add a vCenter instance of a vCenter version 6.7. The error is not very informative:
It doesn’t really scream out what the error is. But as I had seen the error before I had a hunch when my colleague was configuring vRO in our vRealize Automation platform.
On the vRO VMTN forum there is a post that contains the latest release of the vRO VC plugin – https://communities.vmware.com/docs/DOC-32872
Simply download the zip attached. Unpack the vmoapp file. Login to the vRO control-center on https://<FQDNorIP>:8283/vco-controlcenter/ and select “Manage Plug-ins”. Here under “Install plug-in” click browse and select the vmoapp file and upload. Accept EULA and install. After about 2 minutes the vRO will have restarted and the plugin updated.
vCenter instances can now be added 🙂