Hi mwtheplumber,
Thanks for coming back to us and confirming that you're able to log in to TV Go fine.
When trying to sign in to Sky Sports, are you using the app or the website? Please ensure that when the log in options come up, you are clicking on Virgin Media before signing in. Once you've clicked on this, it should load a different log in page.
If you're still having the error message, please let us know the make and model of the device you are using, the OS it's running on and if possible give a screenshot showing the error and we can go from there.
Many thanks,