A distraction error forced users to give up their extensions on Firefox. The problem seems to have been solved, but not completely
If you use the Mozilla Firefox browser to browse the Internet, then you must have noticed that for a few days this software has more than one problem. In particular, since May 3, Firefox extensions (which are called "Add on" on this browser) no longer work. Mozilla is aware of the problem, has apologized to users explaining the cause and has already released a first fix to solve the malfunction.
Everything was born because of a certificate used to sign add ons, which expired at midnight on May 3 causing the block of extensions, language packs and themes. The bug was classified as 159061 and 1549078 and has been largely fixed. Due to the certificate it was not possible for a few days to install new add ons or use the ones already installed. Uninstalling and reinstalling the add-ons did not solve the problem, which occurred on desktop, Android and ESR (Firefox Extended Support Release, the Enterprise version of this browser) versions.
Firefox extensions bug, Mozilla's fix
Mozilla's technical team quickly realized that the problem stemmed from the certificate chain and moved quickly to fix the bug. After releasing a first temporary fix for Firefox Desktop, it has also published version 66.0.4 for Android which, as the official note says, "fixes the certificate chain to reactivate web extensions, themes, search engines and language packs that were disabled. A few issues remain that we are aware of and are working on to resolve." There are still small issues with a small number of add ons: they are listed by Firefox as unsupported, but if the user reinstalls them they very often work. Some add ons may have lost some configuration data while themes (surely the most downloaded add ons by Firefox users) may not be automatically reactivated. In this case, the user will have to do it manually.
How to install the Firefox fix
To fix the Firefox extensions bug you need to install the latest version of the browser (66.0.4) which contains the fix described above. The version for desktop PC can be downloaded directly from Mozilla's website at this address while the one for Android directly from this page of Google Play Store. After doing so, most of the problems should be gone. It is likely that in the coming days Mozilla will release a new version of Firefox to fix the few remaining problems.