Hey @Robert_P_Ellis,
Just to clarify I understand correctly your complaint - you can no longer login your account on Roon Core client ? If so, what exactly is happening after you press Login button ? Does jellyfish (moving Roon logo) spin forever or app return an error? Have you tried to reboot the machine where Roon Cor is hosted ? Are you sure it has active internet connection ?
Furthermore, may I kindly ask you to please provide me with an expanded description of your current setup using this link as a guide.
-Vova