As you know, all versions of Firefox need a new certificate installed to be able to verify extension signatures (all unverified extensions get disabled).

A fix for Firefox 52-59 is in the works, but it hasn't been pushed out yet. In case the pushing out part isn't possible or doesn't work for everyone, the Add-ons team probably will provide a link to install it.

An official announcement will show up on the following page when it's ready:

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

There are *unofficial* and *unsupported* workarounds to get the new certificate if you absolutely cannot wait.

By the way, the Java JRE is a plugin, not an extension. As far as I know, plugins are not affected by the inability to run extensions. Does the Java test page work?

https://www.java.com/en/download/installed8.jsp

Yes, luckily my Java applets still work. But it is hard to use the browser without some of the add-ons.

Thanks for your other reply - I will check that page daily. Hopefully an update will be available soon. However, I will be interested to learn more about the *unofficial* and *unsupported* workarounds.

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

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

There are still unresolved issues that prevent installing the legacy hotfix automatically, but a manual install should work.

Awesome. Worked like a charm!

There is a legacy system add-on planned for older Firefox versions that do not support the hotfix. 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
• Bug 1549604#c51 - ship legacy system add-ons to remediate armagadd-on 2.0

There are still unresolved issues that prevent installing the legacy hotfix automatically, but a manual install should work.

> 52.9

▶ https://discourse.mozilla.org/t/-/39845/33?u=grahamperrin ▶ https://bugzilla.mozilla.org/show_bug.cgi?id=1550793#module-attachments-title ▶ Legacy hotfix for Firefox 52 through 60 (signed)

Feedback here, or in the Discourse topic. Thanks!

We are aware of an issue on May 3 that disabled add-ons. The issue has been fixed in the latest version of Firefox. To upgrade to the latest version with the fix, visit [https://www.mozilla.org/firefox/new/].

If you are unable to update to the latest version, add-ons with fixes are available for older versions of Firefox. See this article [https://support.mozilla.org/en-US/kb/add-ons-disabled-or-fail-to-install-...] for more information.