March 14, 2025 came and went. Your "old" Firefox (or Tor Browser) might look pretty horrible today.

If you are not willing to update to a newer version of Firefox that might break all kinds of stuff for you and disrespect how you want to use your browser, you can either look into a new browser or look for a workaround.

Here is a workaround.

But before you apply it, please keep two things in mind:

1) I am not an expert. I just dabble.

2) I might be secretly evil. Hell, if you don't know me, I might even be openly evil. ;3

Seriously: Consider a user's past actions and your past experiences with them before you follow their advice blindly. And don't just install something without hesitation. Do some checks first. Same goes for "tech support" websites: Don't just look at the top hit labeled "Solution to your Problem. Probably." (I'm paraphrasing here). Take a few minutes to figure out if the author knows what they are talking about. There might be comments. There might be old articles telling you how you should beware of aliens from outer space that want to store your brain in a jar...

I bet most of you didn't read half of what I wrote above. I cannot blame you. You are not in a emotionally good place right now "just" want your stuff fixed. Maybe read the rest later...

Set a bookmark here in case you need/want to look at this again - to undo the changes or to send the link to a friend in need.

To get your Add-Ons running again enter "about:config" into the address bar.

Then search for "xpinstall.signatures.required" and set it to false by double-clicking.

If you were using a language that wasn't English, you can get that back as well:

To get your usual language settings back enter "about:config" into the address bar.

Then search for "extensions.langpacks.signatures.required" and set it to false by double-clicking.

Restart your browser and your language should be back to whatever you had it set to before (likely Spanish or Russian).

What did you (the person reading this) just do?

You set your browser to not check with Mozilla to verify if an Add-On (or language pack) is actually safe to use and/or functional. If it's any comfort to you: Mozilla just don't test most Add-Ons anyway and a lot of Add-Ons do not work as advertised or do not work at all. You can trust your "old" Add-Ons as much as you could before, but you should be careful concerning any Add-Ons you add to that version of Firefox.

Will this workaround fix that problem forever?

"Maybe..."

It's probably not a good idea to use that version of Firefox for an entire decade or something, but at least you can enjoy this weekend without further drama in that regard.

Where did the solution come from?

Surprisingly enough, the official Firefox support page - albeit not in the kind of article you'd expect it in and they sure as hell did not list it for people to use it in the way I described here...

Why did that happen to you (the reader) in the first place? (simplified)

The answer is pretty boring. Basically, you ignored the warning message you might or might not have been getting (depending on the age of your Firefox) - or you thought it wouldn't be that bad, because the wording was as unhelpful as always.

Why did that happen to you (the reader) in the first place? (detailed)

Officially stated reason.

The actual reason is "so that people update their browser. We at Mozilla just can't understand why people wouldn't want to update Firefox as often as possible... We always put so much effort in to change every single part of the interface that people liked before and make it harder and harder for our users to change the interface back to an arrangement that makes sense (like having tab bar right above 'the actual tabs', instead of having it two bars removed from the thing that they are attached to). Also: Our users should rejoice that we keep breaking "old" Add-Ons for the sake of security and then delete the installer files off our site, so nobody can ever find it again to install it on a version of Firefox it would still run on - or pick up the project and port it to a newer version of Firefox." ;p

This Dilbert comic puts it best.

Anything else?

I might or might not update this post (further) in the future. But right now I am too tired for that. And most of you will likely just want your stuff fixed, so your life can go on like you were used to. Which would sound very relatable to me. ;)

I'll make notes at the very bottom of this post to point out updates if any updating takes place.

TL;DR:

about:config

xpinstall.signatures.required = false

extensions.langpacks.signatures.required = false

As always: I hope this helps. You're welcome. Now go enjoy your remaining weekend.

Addendum 2025-03-15: Added links to sources as well as more complaining and a link to a comic strip to make up for it. Sorry that I'm so short on time & energy these days. I'll hopefully improve the wording eventually. Thanks to everybody who liked this post, but it is absolutely okay to pay no attention to it. I bet half of you just wanted to be kind and don't even use Firefox in the first place - let alone an older version... ;)