Hi Kubu08, have your extensions been enabled yet?

If not, did you get the studies related to this fix, or did they never show up on 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

Can't be enabled if they were deleted.

I have no studies. When I go to about:studies page I only see this "What's this? Firefox may install and run studies from time to time."

I'd rather not install the hotfix update. What's the estimate time until this bug will be fixed?

Firefox 66.0.4 is intended to be released today or tonight, once it finishes testing. Not sure about Firefox 60 ESR.

I am not aware of any intention to issue fixes for earlier releases of Firefox. I think you may be on your own to update the certificate. If you don't trust the methods in the thread I mentioned, you can search out confirmation from other sources.

I'm sticking to my older version though as some of the addons I use aren't supported in newer versions and there are no good replacements.

So you say that this fix won't be applied retroactively to all browser versions, only to the newest version and certificate will remain expired on all versions but 66...?

Every Firefox, every version, needs a new certificate. If you do not plan to use one of the official updates, you will need to install it through a different method. I gave a link earlier to a thread that lists two different unofficial methods.

There was a Bug-A-Boo with a Certificate Expiration Date dealing with the Add-ons. There's a new FF Version with the main Fix, 66.0.4.

Mozilla Blog Post Update:
A Firefox release has been pushed — version 66.0.4 on Desktop and Android, and version 60.6.2 for ESR. This release repairs the certificate chain to re-enable web extensions, themes, search engines, and language packs that had been disabled (Bug 1549061).
There are remaining issues that we are actively working to resolve, but we wanted to get this fix out before Monday to lessen the impact of disabled add-ons before the start of the week. More information about the remaining issues can be found by clicking on the links to the release notes above.
(May 5, 16:25 EDT)

~Pj

Kubu08 said

So you say that this fix won't be applied retroactively to all browser versions,

Fix as in a update then yes at the moment.

Firefox 66 and 60 ESR are the only supported Releases at the moment as all other versions are End Of Life or EOL.

Firefox 56.0 was made EOL when Firefox 57.0 was Released.

Kubu08 said

I'm sticking to my older version though as some of the add-ons I use aren't supported in newer versions and there are no good replacements...

Additional Info: From Mozilla Blog:

Updates – Last Updated: 19:28 EDT May 8 2019

We’ve released Firefox 66.0.5 for Desktop and Android, and Firefox ESR 60.6.3, which include the permanent fix for re-enabling add-ons that were disabled starting on May 3rd. The initial, temporary fix that was deployed May 4th through the Studies system is replaced by these updates, and we recommend updating as soon as possible. Users who enabled Studies to receive the temporary fix, and have updated to the permanent fix, can now disable Studies if they desire.

For users who cannot update to the latest version of Firefox or Firefox ESR, we plan to distribute an update that automatically applies the fix to versions 52 through 60. This fix will also be available as a user-installable extension. For anyone still experiencing issues in versions 61 through 65, we plan to distribute a fix through a user-installable extension. These extensions will not require users to enable Studies, and we’ll provide an update when they are available.

"Updates – Last Updated: 11:51 EDT May 8 2019

Firefox 66.0.5 has been released, and we recommend that people update to that version if they continue to experience problems with extensions being disabled. You’ll get an update notification within 24 hours, or you can initiate an update manually.
An update to ESR 60.6.3 is also available as of May 8th. We’re continuing to work on a fix for older versions of Firefox, and will update this post and on social media as we have more information."

~Pj

https://support.mozilla.org/en-US/questions/1258165#answer-1218833 fixed the issue for my v54.

You will have to install the new intermediate certificate to replace the exipred certificate.

See comment 51 in bug 549604 for a link to install the legacy version of the hotfix extension to install the intermediate certificate.

• hotfix-update-xpi-signing-intermediate-bug-1548973-legacy@mozilla.org-1.1.2-signed.xpi
• https://bugzilla.mozilla.org/show_bug.cgi?id=1549604#c51

See also (thanks James):

• https://hacks.mozilla.org/2019/05/technical-details-on-the-recent-firefox-add-on-outage/

I also hate version 66 for another major reason - killing any of the processes in task manager kills the whole browser. This was not the case in 56 version. I could just kill 1 biggest process and it would only kill one tab that was being unresponsive or used too much memory instead of killing the whole browser.

Should probably post a new question for that - but I have 8 firefox processes allowed by default and help article mentioned 8 default number is good for users with +8 GB RAM. I only have 4 GB available for my whole PC...

Kubu08 said

I also hate version 66 for another major reason - killing any of the processes in task manager kills the whole browser.

I have not tested that. However, why would you need to kill a process in Task Manager? Can you determine a problem tab and close it?

Kubu08 said

Should probably post a new question for that - but I have 8 firefox processes allowed by default and help article mentioned 8 default number is good for users with +8 GB RAM. I only have 4 GB available for my whole PC...

You can set a different number of Content processes on the Options/Preferences page: Firefox's performance settings

jscher2000 said

You can set a different number of Content processes on the Options/Preferences page: Firefox's performance settings

What would be a good number for 4 GB ram available so that my browser isn't hogging too much memory?

Kubu08 said

jscher2000 said

You can set a different number of Content processes on the Options/Preferences page: Firefox's performance settings

What would be a good number for 4 GB ram available so that my browser isn't hogging too much memory?

Try 4, which is what it was from Firefox 54-65 (or around there).

Most of the memory is used by the content itself; I don't think the overhead of dividing it into smaller buckets is the main problem.

@jscher2000 I thought after updating to version 66 I wouldn't get high memory usage alerts anymore but apparently multi-process feature did nothing to help decreasing RAM usage and I still get the alerts.

Kubu08 said

@jscher2000 I thought after updating to version 66 I wouldn't get high memory usage alerts anymore but apparently multi-process feature did nothing to help decreasing RAM usage and I still get the alerts.

What version were you using before? Firefox has been a multi-process application starting in Firefox 48 with two content processes, doubling to four in Firefox 54, doubling to eight in Firefox 66.

Does anything in this article help: Firefox uses too much memory or CPU resources - How to fix.

@jscher2000

Firefox 56 - I'm not sure if it was 56.0, 56.0.1 or 56.0.2 since the update history is gone and only shows the last update. I only have two addons installed currently, that is Adblock and Undo Close Tab.

jscher2000 said

I have not tested that. However, why would you need to kill a process in Task Manager? Can you determine a problem tab and close it?

Also, about this. I had several firefox processes, now I have 11 from what I counted, the biggest one is using about 430K RAM.

In that previous version I had less processes and one of them would usually bloat to over 1,700K or even 2,000K. When I killed that process it only killed my working tab without killing the whole browser and that tab would display this message:

(found it on net but it was the same except in Polish)

I could safely close that tab and my browser didn't crash and the result would be decrease in RAM usage.

I found this crash report and have been using that version till April this year. So it's Firefox 56.0.2.

I guess also I had multi-process application disabled, cause it was set to 1. Unless that means something else and I'm reading it wrong.