getadblock.com is free and Firefox loves it. It should update to version 3.29.0 once you install it. I've had it on my system for eons and far prefer it over Adblock Plus.

I just read about this on another forum. Somebody said theirs was no longer working while others were having no problem. Me included, so far I still see the Adblock Plus icon and no ads.

Well...shoot! No sooner did I reply to your quest, Gadgets. than Firefox closed AdBlock down on my PC, as well. Something a bit strange going on here. If I have success in retrieving it...I'll report back here. Sorry!

Uh-oh. so far so good on mine.

Tried downloading both AdBlock and AdBlockPlus from FileHippo.com. No go! Both apps say I must download Google Chrome to get either of these apps. I don't like Chrome so I guess that's it for the moment. It's not like Firefox to drop an app like this without some warning to us users. Something is amiss here...IMHO.

I'll keep my fingers crossed because at the moment my Adblock is still enabled.

It's a known issue, a security certificate expired and caused tons of add ons to quit working.

"Mozilla has begun automatically distributing a Firefox update to fix a problem that broke extensions for many browser users on Friday.

Extensions, also called add-ons, let you customize browsers to do things like block ad tracking or offer video-playback speed controls. Mozilla requires they be digitally signed to improve security. The certificate Mozilla uses for that purpose expired, though, so Firefox started disabling extensions it no longer considered safe"

I left to go watch the Ky Derby. What a waste of my time! I found this online, so think I'll wait a while before doing anything else. Thanks to all who responded. I'll gladly read any/all suggestions.

Thanks, Texas. Your info is appreciated. They dropped HTTPS Everywhere, too. And, there's no ad block program that will down load right now. I've tried them all. Firefox is blocking everything of that nature. I hope they get their act together soon. This situation is not exactly safe.

https://adblockplus.org/blog/firefox-bug-disabled-all-add-ons-including-adblock-plus

It's a bug. Update Firefox for the fixes to Firefox.

I have the latest version of Firefox, Raven. They must be rolling out this current update very slowly. I'll just keep checking back. Thanks.

"They must be rolling out this current update very slowly."

Yeah, I hoped they'd have it fixed by now.

As a temporary fix, I installed the Nightly build: https://www.mozilla.org/en-US/firefox/nightly/all/

and set the key "xpinstall.signatures.required" to false. (using about:config)

I had also backed up my Firefox profile directory.

After starting Nightly (so it creates a profile), I copied my backup profile into it. (That way I still had my bookmarks, etc., as well as my extensions)

Probably other ways but that's how I did it.

Goes something like this:

All of my extensions had vanished except one.

Toggling xpinstall.signatures.required to false causes them to immediately reappear:

I use adblocker ultimate on Firefox and have had no problems with it.

https://blog.mozilla.org/addons/2019/05/04/update-regarding-add-ons-in-firefox/

Seems to fix it.

I haven't looked through Richard's link yet, but last night Firefox informed me it could no longer allow adblock, or the 'no squint' ad ons. Then they disabled both. I haven't really noticed a difference in ads, but then wasn't home this afternoon or this evening to have done much in the way of browsing. My ebay page looks different/smaller without 'no squint'.

Morz it was a bug, it disabled all add ons.

Your addons should all be back now. Firefox was working hard to correct it. They did say, that you might have to tell adblock plus what you wanted blocked all over again, but, that wasnt the case with mine. It seems to be exactly as it was.

Sorry, cat, I'm still without any of my addons, including adblock. I'm not going to try to 'do' anything. I just pray that mine is fixed very soon.

" ... Some users are reporting that they do not have the
“hotfix-update-xpi-signing-intermediate-bug-1548973” study active in
“about:studies”. Rather than using work-arounds, which can lead to
issues later on, we strongly recommend that you continue to wait. If
it’s possible for you to receive the hotfix, you should get it by 6am
EDT, 24 hours after it was first released. For everyone else, we are
working to ship a more permanent solution. (May 5, 00:54 EDT)"

Yes, waiting seems to be the latest recommendation from the Mozilla Add-ons Blog linked above.

Gadgets you might want to have Firefox check for updates. They are trying to get it out to everyone. Do not delete your add ons! If you left them as they were your settings should be kept as they were.

This "fix" does not show up as an update...and checking for updates does nothing. When it arrives...you'll just see your add ons reappear in all their glory. If you haven't fiddled around with them while waiting for the solution...they will have all their previous settings and you won't have to do anything. They go back to work and happiness returns.

At 10:00 AM something this morning...mine weren't fixed. But checking in later at 11:45 AM...they were. It's just taking time.

At Noon mine did not work. 4:30PM everything is working fine ( Adblock Plus and my themes ).

I downloaded AdGuard, and it seems to be working fine, will continue to use it until AdBlock Plus is usable again. Or maybe I'll just keep AdGuard instead.

Gadgets and those of you that havent received the fix yet, go to tools and options and click on privacy and security. Scroll all the way down to firefox data collection. Underneath it is 3 boxes, allowing firefox to do do things. The one in the center for studies is the one that needs to be checked, but, on mine, I had to check all 3 to get that one to work. Thats how they are getting the fix into your computer. If yours are disabled, they wont be able to do that. Once everything is fixed, you can go back and uncheck them all.

cat and all who answered. I did the studies thing late yesterday. It took a while but I then looked for updates and there was finally one there. I had to do it twice before it actually updated. Now all seems to be fine. My Yahoo is okay also.

Thanks for all the info I got on here. I will now go back and uncheck them all.

My Firefox repaired itself yesterday but this morning there was an update installing itself when I opened it.

It removed my ad blocking add-ons until the update this morning. Once I updated Firefox, it added them back?