Firefox – with Legacy addon support downgrade to 56.0.2 windowsPosted: 15/11/2017
NoScript now supports the new Firefox version 57! I do not recommend you to downgrade Firefox unless you absolutely have to use other legacy addons.
The latest Firefox 57 “Quantum” version no longer supports legacy addons.
You can check the current status of some popular addons migration in to WebExtension on this documentation page.
In order to use legacy addons first you need to disable automatic updates in Firefox under Tools->Options->General and then downgrade your Firefox Version. Not bringing up the issues and potential risks with using old software (security wise) this is easy to do. All you need to do is retrieve and download the old installer and reinstall over the previous version.
If you are only swapping between version 56 and 57 your profile storing all your settings and bookmarks will remain the same and unharmed. I’ve been swapping back and fourth on the same profile for a while without any issues. Please note that downgrading to very old versions can however cause issues however.
Unfortunately Mozilla has made it a bit difficult to locate the downloads of previous versions and the top Google results (as of checking today at least) unfortunately links to unreliable third party download sources. A typical modern phenomenon which appears to become more common. Always avoid downloading software from unofficial sources. Try to make a habit of checking domains names carefully.
If you know your language codes you can browse the official Mozilla Version history directory and download version 56.0.2 from there. In case you don’t know the language codes then you can check your language version of Firefox from the Mozilla and modify the download link URL. Click here to view the official list of different downloads and languages.
The following link example is for the 64 bit windows version with Swedish Language. Scroll down for some quick link examples.
The original URL links to the latest Swedish (sv-SE) version:
We edit that to point to 56.0.2 Swedish (sv-SE) version instead:
Some language specific direct link URL version 56.0.2 downloads
Firefox 56.0.2 – English American (en-US) 64 bit
Firefox 56.0.2 – English British (en-GB) 64 bit
Firefox 56.0.2 – Swedish (sv-SE) 64 bit
Firefox 56.0.2 – Danish (da) 64 bit
Firefox 56.0.2 – Norwegian Bokmål (nb-NO) 64 bit
After downloading it’s as easy as running the installer and clicking next, next and then upgrade. This is the same procedure used to change the language of Firefox’s user interface.
Settings wise – changing between version 56 and 57 is safe. All your profile settings and bookmarks will remain the same.
This is a temporary solution until (hopefully) NoScript or an equivalent feature gets supported somehow in the latest version of Firefox 57 Quantum.
I wrote this guide as a basic “for dummies” guide that I can link to whenever I get the question: Why have my Firefox addons stopped working?