Suddenly can't get to email page - XFinity

Suddenly can't get to email page, XFinity-Comcast internet. Today, When signing on to Xfinity page on my desktop, the email envelope icon shows 99+ in red, and when I click on the icon, I'm sent to a new sign-in page. Unable to get to the email page. My iphone, on the other hand, shows me my emails ok. It shows no new emails. What can I do? Previous messages on this forum hint at the same problem, but so far I don't see a solution. Thanks