Experiencing "threat has been detected" nearly every web page

Have been using Avast for years, first time this has happened. Config info:

Win 7 (up to date)
Chrome (up to date)
Firefox (up to date)

Happens regardless of browser. In safe mode, have run SuperAntiSpware, Malwarebytes, and CCleaner. Ran Avast boot scan.

Still occurs…suggestions? The only way to stop it is to disable web shields and I don’t want to do that. Thanks.

how to recive help instructions https://forum.avast.com/index.php?topic=53253.0