A lot of you people using Firefox probably already realized: The update to Firefox 43 completely disables New XKit due to it not being signed/verified.
Let me begin by saying that all of us are truly sorry for this inconvenience.
We are trying our best to fix this but currently are unable to give an ETA on how soon this is going to happen.
Mozilla published their plan for extension verification in Feburary, so even when the New XKit project started in July we knew that it was something we were going to have to deal with eventually. We submitted our extension initially to Mozilla on July 20th, and did not hear back from them until November 16th, when Mozilla removed our extension from their online gallery, telling as that we do not meet their requirements to be a publicly listed extension. We then submitted as an “unlisted” extension, which was theoretically a more lenient process. This time they got back to us within about a week, but they would not still not accept the extension the way it was currently written.
There are a lot of technical details that go into the situation, but the bottom line is that we need to rewrite the core of how XKit handles extensions almost completely before getting signed. We’re currently about half-way through that process, and hope to have something to share with you as soon as we can pass validation. The biggest downside that comes with this rewrite though will be our reaction time—we will have to update the entire extension whenever we want to change one of the individual packaged extensions, and third-party (non-signed) XKit Extensions will no longer work.
Until signing happens though, we can offer you 3 workarounds:
- Use another browser like Chrome or Opera with New XKit. This is the best solution, as it allows you to still be on the most up-to-date browsers while also using New XKit. You can grab the Chrome version of New XKit from the Chrome Web Store and find instructions for using New XKit with Opera on our blog
- Downgrade Firefox to v42. This is less recommended then option 1, but more recommended the option 3. Mozilla provides instructions on how to do this on their wiki
- Disable signature checks in Firefox v43. (NOT recommended)
WARNING! Signed extensions a security feature added by Mozilla. Disabling that feature may put you at risk of installing viruses and ad-ware!
Additionally, this fix only works until Firefox v44 hits and the switch gets removed.
If you still want to proceed, type “about:config” in your Address Bar, look for “xpinstall.signatures.required” and double click on it so it has the value “false”.
And as always, if you got any trouble with XKit, you are welcome to join our support chat room. (hosted on gitter, if you want to join with a github account)