Now, Mozilla has fixed the critical issues with the release of Firefox 66.0.4.
The Open source company was made aware of a critical bug in the latest Firefox 66.0.3 release of its popular web browser for desktops and mobile platforms, which apparently prevented new and existing add-ons, themes, search engines, and language packs from being installed or run.
The users widely reported that Firefox is not allowing them to install many of the listed add-ons and the existing extensions have also been disabled. Findings revealed that bug is related to an expired certificate.
Mozilla immediately took action and pushed a temporary fix via OTA (Over-the-Air) updates to all users on desktop platforms, which includes Linux, macOS, and Windows systems, for all available channels. The users are also informed that there is no need to delete their installed add-ons for the issue.
With the releasing of new version Firefox 66.0.4 and Firefox 60.6.2 ESR, Mozilla is repairing the broken certificate chain and also has re-enabled add-ons that had been disabled.
The data of add-ons such as Multi-Account Containers, Facebook Container and others that use Containers functionality cannot be recovered. You have to set up these add-ons again and login back to continue using them. The themes may not be re-enabled automatically after installing this update, so you may need to re-enable them from add-ons page again. If you used an add-on to customize the homepage or search settings, the customizations would reset to defaults and you may need to customize the experience again.
The new versions are made available by the maintainers of their GNU/Linux distributions via the official software channels. It would appear that many issues are still present even after installing these versions. Mozilla promises that it constantly works on fixing all related problems, so expect a new version soon.
Mozilla recommends installing Firefox 66.0.4 as soon as it's available in your repository.