"The requested URL was rejected. Please consult with your administrator."

I installed a new Xfinity gateway, and now I cannot access Sling from my laptop, phone, or AppleTV. I do not have this issue when switching back to the old modem.

On the laptop browser, I get the following error:

The requested URL was rejected. Please consult with your administrator.

Your support ID is 36a9c1fa-703e-4997-b1d6-08d75b9af849