Same issue. All was working fine and then after being at school and conneting to the non-xfinity net work, after leaving the campus the xfifnity connection asked for the my user name and password and has failed to connect ever since. I've entered the user/pass a dozen times and it gives the same mesaage that you posted with or without uisng the xfinity app.
Phone: BLU R1 HD
Is anyone at Xfinity monitoring ?!