Many Firefox users around the world lost their usual set of extensions due to their sudden disabling. This event occurred after midnight UTC on May 4th — the issue is related to the expiration of a certificate used for generating digital signatures. In theory, the certificate was supposed to be updated a week ago, but for some reason, it did not happen.
The same problem occurred almost three years ago, and now in a conversation with Engadget, product leader Kev Needham stated: “We regret that there is currently an issue preventing existing and new extensions from launching or being installed in Firefox. We know what the problem is and are making every effort to restore this functionality in Firefox as soon as possible. We will continue to provide updates through our Twitter channels. Please bear with us while we fix the issue.”
At the moment, there is at least one workaround, but it can only be used with the Firefox Developer version or early Nightly builds. If you go to the 'about:config' section and set the xpinstall.signatures.required parameter to False, then extensions will start working again.
If another version of Firefox is being used, there is a way to temporarily fix the issue, but the user will have to repeat it each time they open the browser. This involves enabling the extension debugging mode and manually loading .xpi files for each of them.
