There is a problem with the certificate that is used to sign some extensions. This is being worked by the Add-ons team.

See:

• [/questions/1257928] Will the disabling of add-ons be fixed, or is it the new way?
• https://discourse.mozilla.org/t/certificate-issue-causing-add-ons-to-be-disabled-or-fail-to-install/39047

At about 6:10 PST we received a report that a certificate issue for Firefox is causing add-ons to stop working and add-on installs to fail.
Our team is actively working on a fix. We will update as soon as we have more information.

Mozilla has rolled-out a fix for this. The fix will be automatically applied in the background within the next few hours, you don’t need to take active steps.

In order to be able to provide this fix on short notice, they are using the Studies system. You can check if you have studies enabled

1. Go to [=] > Options > Privacy & Security.
2. Make sure Allow Firefox to install and run studies is check marked.

I you had it disabled, you can disable studies again after your add-ons have been re-enabled.

They are working on a general fix that doesn't need to rely on this and will keep you updated.

See also:

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

I did all that i was told to do and still nothing i went to the studies page and there were no active studies at all now what is the problem.Why does Mozilla just roll back to the last update and fix the problem and then update us .

Hi Rick, this isn't related to your Firefox version, we've had posts from users of Firefox 48, 52, 54, 56, 60, 66, and 67 in the forum in the past 24 hours.

It has been a few hours since you posted. Did you get the studies related to this fix? They might be listed in the Completed section of the about:studies page.

If you got the studies, check whether the certificate was added. That would be on the Options/Preferences page:

• Windows: "3-bar" menu button (or Tools menu) > Options
• Mac: "3-bar" menu button (or Firefox menu) > Preferences
• Linux: "3-bar" menu button (or Edit menu) > Preferences
• Any system: type or paste about:preferences into the address bar and press Enter/Return to load it

In the search box at the top of the page, type cert and Firefox should filter to the Certificates section. Then click the "View Certificates" button. Check the "Authorities" tab to see whether Mozilla is listed with the new certificate. You can compare the attached screenshot.

If you got no studies and no certificate, try the manual method listed in this reply and/or the ones that follow: https://support.mozilla.org/questions/1258208#answer-1218876

Again when i load the page that show the studies it tells me that there is no active studies ,so i did what the last guy asked me to do and again nothing happens at all.Why do we have to do this anyway there are millions of us users and it would just be simple to turn back the update in till you guys fix it wow wow wow wow wow i am really getting peeved with all this, This is not the first time Firefox has rolled out an update that was crap ,i know it happens but wow why do you not test it before you roll it out to the public.I just do not understand why it can not be rolled back.

Hi Rick, this was not an update, it's the opposite: someone failed to update a certificate and it expired.

So you do not have any Active or Completed studies? If you have any Completed studies do any of them mention "xpi"?

Also, what exactly did you try after my last reply?

I want to Thank you jscher2000 i do not know what i did but they are now up and running.I do have another question everytime i open up My FireFox Browsers it opens just about 5 maybe 6 other windows lol they are all connected to FireFox when i was trying to find out what happen and try to re download my addons when i did not know i couldn't ,i have reopened the browser many times since yesterday but still they come up at the same time my browsers does.Thank you again you are a blessing.

Hi Rick, progress is good.

There are three possible reasons to get back old windows or tabs. (Maybe more, but these are the most obvious ones...)

(1) Firefox may be set to Restore Previous Session on the Options page. You can check here:

• Windows: "3-bar" menu button (or Tools menu) > Options
• Mac: "3-bar" menu button (or Firefox menu) > Preferences
• Linux: "3-bar" menu button (or Edit menu) > Preferences
• Any system: type or paste about:preferences into the address bar and press Enter/Return to load it

It's in the first section of the first panel (General).

(2) Firefox may be performing a crash recovery

If Firefox doesn't shut down normally, it will automatically restore your previous session. Have you noticed any problems with how Firefox shuts down when you use the Exit command? Either:

• "3-bar" menu button > Exit
• (menu bar) File > Exit

(3) Your home page setting might have changed to a list of pages, each of which will open in a separate tab (usually not a completely separate window)

This article has the steps to review/update your home page setting: How to set the home page

(Any Windows 10 users reading? This is another possibility for you: Firefox starts automatically when I restart Windows)

Right again ,some how all those pages became my home page lol wow so simple Thank you so much jscher2000.