Sorry, this not a Firefox support issue. It sounds like issue with the 3rd party Avast add-on for Firefox. I suspect that you need another Avast & Firefox user to help you figure that out (in that thread DavidR shows Firefox 39.0 in his signature), or file a Bug report with Avast on that "Browser protection module".

Whether it works in IE11 or does, or does not work in Opera as commented in that Avast thread, has no bearing on what happens in Firefox. Trident (IE), WebKit (Opera & Chrome), and Gecko (Firefox, SeaMonkey, & others) browsers all use their own "addons" coding and can't be compared for troubleshooting purposes at the browser level - the addons are particular to each "browser engine".

Personally, I avoid security suites that "insist" upon installing add-ons for Firefox as they are usually more trouble than they are worth. In my experience most of those "addons" duplicate features that are already built into Firefox; "added" features rarely work as well as what is in Firefox. Or the "security" company cant keep their "stuff" up-to-date with Firefox releases, leaving the user without that dubious "protection" until the security vendor provides an update.

I was thinking I might de-install the Browser protection module, and install Web of Trust . . . then it would tell me about web pages in search, with the color coding . . . have you ever tried WOT?

I think Avast passed all the AMTSO tests, except the second one, but I think nothing got downloaded, not sure, and not sure why, I will re-try it.

No, I have never tried WOT - personal opinions of internet users about websites doesn't make for much of a "security" feature, IMO.

This has proven to be enough protection for me. https://support.mozilla.org/en-US/kb/how-does-phishing-and-malware-protection-work

Thanks, I'm going to de-install it, and see how it goes.

I will de-install the Home Network Security 3rd party also.