This error typically occurs when a VyprVPN Premium user already has a registered server, since you are only allotted a single registered server with those account levels. Most commonly this happens if the user deletes their server and fails to deregister the VyprVPN Server first.
To remedy this error, follow the steps in "How do I deregister a server?"
If you need any further assistance, please contact our 24/7 Customer Success Team, who would be glad to assist.