Is there any answer to this, I'm getting it too?
Google found this:
Resolved in Chrome 60 for Windows. These steps worked for me:
Now on my Mac, I cannot stream xfinity on ANY browser. Even though Flash is installed and enabled, both Firefox and Safari and Safari Technology Preview do not stream. I keep getting asked to enable flash, and I did, following the links.
And Microsoft Edge Beta gives Xfinity Stream is not available at the moment. Please try back soon.
It is based on Chromium.
Google Chrome stopped working also, but is now working again.
Xdfinity should replace Flash with HTML 5 or some other technology. It is too insecure.
Greetings jarom! I appreciate you taking the time to reach out to us here on the forums. I hope you are having an amazing day. I apologize to hear you are having issues with trying to stream. That's certainly frustrating as we want you to be able to enjoy the streaming services. I would like to look further into this for you. Can you please send a PM with your first and last name so I may further assist you?
To send a private message, please click my name "Comcast_Support" then select "Send a Message" on the right side.