Thanks for sharing your experience here on the Xfinity Forums. Normally, that error message is triggered when you don't have and xFi compatible gateway. If you don't have a modem listed on this list and would like to upgrade so you can manage your network using xFi, send me a private message with your first and last name and I can ship you a compatible Comcast gateway. There will be a monthly rental fee if you decide to switch. To send a private message, click on "ComcastChe" and then click "send a message."