Firefox Add-Ons Disabled? Here’s How to Fix It.

On Friday night (May 3rd, 2019), Many users of Firefox noticed that their add-ons (extensions) suddenly stopped working. Mozilla (makers of Firefox) worked hard all weekend to correct the problem, which they went into some detail about here.

Better, more detailed articles, for those who care about the technical reasons of what happened, can be found here (Engadget) and here (Bleeping Computer).

For most people, not having add-ons is an inconvenience, but for some it’s a need. For those on limited data plans, including mobile, ads can eat up a lot of data, so Ad blockers do have their legitimate uses. Mom and I depend on LastPass, so that was also disabled, and thus we couldn’t easily log into our banking, for example. Thankfully nothing urgent in our case, but still irritating.

The next morning (Saturday), Mozilla released a temporary fix for the issue, which was being rolled out to ALL users of Firefox, supposedly within a 6 hour time frame. That said, many users, including my Mom, had to wait longer.

Why Mozilla didn’t just put a link on their website or blog post to download the fix isn’t clear, but they did include it in tweets for some reason. So, I downloaded and installed it on my secondary computer and Mom’s computer and it worked instantly.

You can download the fix here.

You will see this pop-up when you click that link. No need to worry. Go ahead and click ‘Add’. The fix will take effect instantly and your Add-Ons will work again.

If for some reason they don’t, the newest version of Firefox with that link included is now available (as of Monday). Go to, or click the ‘Hamburger’ icon in the top right of Firefox, then ‘Help’, then ‘About Firefox’, and click the ‘update to 66.0.4’ button.