When clicking on the Join to One Identity Starling button in the Active Roles Configuration Center, the following error message is encountered:
An unexpected error has occurred.
Add *.cloud.oneidentity.com to Trusted Sites in the Internet Explorer settings.
If these settings are enforced by Group Policy and cannot be edited, then it will be necessary to edit the Group Policy to allow communications to the Starling endpoints from the Active Roles host. For more information on this option, please see this Microsoft resource.