Firefox broke add-ons because it let a security certificate expire

What should have probably been an uneventful weekend, or a weekend spent watching Avengers: Endgame, turned out to be a mini-nightmare for the folks at Mozilla. The developers of the Firefox web browser spent the past two days feverishly working to re-enable users’ add-ons that suddenly became unusable on Friday night. All because Mozilla forgot that a critical security certificate …