First, if you are using content blockers in your browser on the machine with which you’re logging in, try disabling them and logging back in again.
Diagnostics indicate that you might be using RoonServer in a location known to have geographic internet restrictions and that you’re relying on a consumer VPN to reach upstream services essential to RoonServer’s function.
Unfortunately, it’s beyond Roon’s control to assist with this issue, since the steps you’ll need to take are within the VPN itself. You might find success with a different VPN entirely.