Many Firefox users around the world are browsing without their usual set of extensions after they suddenly stopped working earlier this evening. The event occurred as the clock rolled over on UTC (Coordinated Universal Time, aka GMT or Greenwich Mean Time), and impacted users quickly narrowed it down to “expiration of intermediate signing cert” — as it’s described on Mozilla’s bug tracker.

This same problem almost happened three years ago, but “armagadd-on” 2.0 apparently caught developers by surprise. A post by Caitlin Neiman on Mozilla’s forums confirmed the issue, although there’s not yet any timeline for a fix:

At about 6:10 PST we received a report that a certificate issue for Firefox is causing add-ons to stop working and add-on installs to fail.

Our team is actively working on a fix. We will update as soon as we have more information.