Some different things to try------------
1) Clear out your browser's cache, including cookies, then close it out and re-start it. If that doesn't do it, then
2) Try a different browser. If you are using IE try Firefox or Chrome.
3) Which version of Xfinity connect are you using--Lite or Full? You can check by going to Preferences>>>General and seeing which is checked. If you're on Full try the Lite. It's more basic but lots of folks have had good results with it.
4) As a temporary work-around, you can use m.comcast.net--------the mobile version. Very basic but it allows you to function.
Let us know if any of that helps.
