To protect Firefox users from malicious add-ons, Mozilla has announced extension signing and they’ve started to sign add-ons in AMO, meanwhile, add-ons manager in Nightly or Firefox 40 now showing a warning notification for unsigned add-ons (they’re not disabled): ‘[add-on name] could not be verified for use in Nightly. Proceed with caution’, with More information link points to this page (check the screenshot below). 

Mozilla will begin requiring all extensions to be signed in order for them to be installable in Release and Beta versions of Firefox. Signing will be done through AMO and will be mandatory for all extensions, regardless of where they are hosted.

warning for installed unsigned add-on

READ:There will be a Firefox 38.0.5 Spring Release in between v38 and v39

By default, Mozilla has disabled Signature check for add-ons in Nightly, but they want to show a note when that  happens — FYI xpinstall.signatures.required preference value being set to ‘false’ –that’s why you’re now seeing the errors, otherwise  your add-ons could’ve been disabled.

For more information, read this bug 1149702 Display a note about add-ons that aren’t properly signed in the add-ons.

Firefox 40 gets Task Manager Feature

Disabling Signature checks

All Firefox channels check for add-ons signature, users who want to install unsigned add-ons can disable signature checking in Nightly and Aurora versions by using a preference, but it’s not possible in Firefox Release and beta versions, this applies to Firefox 41.

Do you think this will annoy Firefox release and beta version users, as they use them the most?