Hello James,
It just means that the ProgramID in your RFC destination is not registered as a JCO User in the PI system. To do this:
1. Go to NWA, the URL should be http(s)://host:port/nwa
2. Then go to Configuration Management -> Connectivity -> Jco RFC Provider
3. Create a JCO User and provide the details of the your XI system under the Server Configuration
4. Save and Start the service.
Hope this helps,
Mark