How do I downgrade Firefox v. 57 to v. 56?

Question

What is the most straight forward way to downgrade Firefox 57 to Firefox 56?

This is to have more time to wait for working replacements for legacy extensions.

Answer 1

I think it is better to downgrade to Firefox ESR 52 (this branch is planned to be supported until 2018-06-26 and will get security updates).

You have two options here:

• Get Firefox ESR 52.5.0 from Jonathon F's PPA. See my answer on a similar topic. You can install the package on 14.04 LTS (Trusty Tahr) and 16.04 LTS (Xenial Xerus) from this repository with the following commands:

  sudo add-apt-repository ppa:jonathonf/firefox-esr
  sudo apt-get update
  sudo apt-get install firefox-esr
  

Or

• Get Firefox ESR 52.5.0 from Mozilla Team's PPA (the first versions were published here at 2017-10-11 as the result of discussion on the ubuntu-desktop maillist). You can install the package on 14.04 LTS (Trusty Tahr), 16.04 LTS (Xenial Xerus), 17.04 (Zesty Zapus), 17.10 (Artful Aardvark), and 18.04 LTS (Bionic Beaver) from this repository with the following commands:

  sudo add-apt-repository ppa:mozillateam/ppa
  sudo apt-get update
  sudo apt-get install firefox-esr
  

For your information:

• The feature request for the official ESR package is located in Launchpad bug 1676164 and on the ubuntu-desktop maillist. Today I wrote a fresh message to this mail list with a link to the current question. I asked similar question on new community.ubuntu.com today.
• The current status of porting LEGACY extensions to WebExtension are located in Google Spreadsheet. The percentage of WebExtensions is not too high.

Answer 2

Disclaimer:

It is not recommended to keep packages on hold unless your goal is to have a stable production environment where the tools you use should not undergo changes while you work with them.

For doing this you can simply do the following:

1. For Ubuntu 17.10:

   Note: this works in artful all the time because artful got released with firefox being version 56.

   # see footnote (1)
   sudo apt-get install firefox=56.0+build6-0ubuntu1
   sudo apt-mark hold firefox
   

2. For Ubuntu 16.04

   Note: this will only work on 16.04 if you did not clean out the cache of youre archives with sudo apt clean or sudo apt autoclean. If you already cleaned your local archives you can only revert to 45.0.2+build1-0ubuntu1 which was the one xenial got released with, alternatively you can refer to @Michael Johnson's answer below which will work fine in this case.

   # see footnote (1)
   sudo apt-get install firefox=56.0+build6-0ubuntu0.16.04.2
   sudo apt-mark hold firefox
   

3. For all other Ubuntu versions:

   Note: Here as well it will only work if you not cleaned your local archives yet:

   request the apt policy information which will return you something like this:

   $ apt policy firefox
   firefox:
     Installed: 57.0+build4-0ubuntu0.17.10.5
     Candidate: 57.0+build4-0ubuntu0.17.10.5
     Version table:
    *** 57.0+build4-0ubuntu0.17.10.5 500
           500 http://archive.ubuntu.com/ubuntu artful-updates/main amd64 Packages
           500 http://archive.ubuntu.com/ubuntu artful-security/main amd64 Packages
        56.0+build6-0ubuntu1 500
           500 http://archive.ubuntu.com/ubuntu artful/main amd64 Packages
           100 /var/lib/dpkg/status
   

   We are after the line which tells you the package name for version 56, which would be in this example 56.0+build6-0ubuntu1. this you simply put into the following lines:

   # see footnote (1)
   sudo apt-get install firefox=<package version>
   sudo apt-mark hold firefox
   

4. If all options above fail you can download older firefox versions on their website for all versions and set them up in your home directory. See How do I install a tar.gz or tar.bz2 file on how to do this. This would leave you with firefox 56 as a second option on your system while you wait for your favorite add-ons to be updated.

5. Since I'm not want to plagiatize @Michael Johnson's answer you should refer to his answer for another fine option on how to revert back.

Whenever you feel you want to update this package again to 57 or whatever version is current then, you can simply do (see (2)):

sudo apt-mark unhold firefox
sudo apt update
sudo apt install firefox

When you start the downgraded firefox for the first time you might get a warning that some extensions (language) which are available in firefox 57 are not compatible with version 56. After one time checking those for updated versions, which will find none, firefox will start normally.

---

^Footnotes:

^{(1) The first will install the last version of firefox 56, even if you have 57 already installed and the second command will block this package from updating (see (2)).}

^{(2) Normally holding/unholding firefox alone suffices for what you want to achieve, but if in doubt holding/unholding 'firefox\*' will hold/unhold all additional packages beginning with firefox too.}

Answer 3

The other answers do not currently work without reading the comments, so I think it is useful to post a more direct answer, since the OP asked for "the most straightforward way". If you are using Ubuntu 16.04 64 bits just run these commands:

wget https://launchpad.net/~ubuntu-mozilla-security/+archive/ubuntu/ppa/+build/13537983/+files/firefox_56.0+build6-0ubuntu0.16.04.2_amd64.deb
sudo dpkg -i firefox_56.0+build6-0ubuntu0.16.04.2_amd64.deb
sudo apt-mark hold firefox

If you are running instead Ubuntu 17.10 (32 or 64 bits), run these commands instead:

sudo apt-get install firefox=56.0+build6-0ubuntu1
sudo apt-mark hold firefox

If you are running some other version of Ubuntu, you'll have to hunt down the .deb here and install with dpkg as above.

Answer 4

You can download the Firefox packages for Ubuntu from http://archive.ubuntu.com/ubuntu/pool/main/f/firefox/. At the end of the list you'll find the the Firefox packages, ignore the other ones (e.g. firefox-dbg, firefox-locale, etc.). From the ones at the end of the list, make sure to select the correct Ubuntu version and CPU architecture.

For Ubuntu 14.04:

• 32-bit
• 64-bit

For Ubuntu 16.04:

• 32-bit
• 64-bit

For Ubuntu 17.04:

• 32-bit
• 64-bit

For Ubuntu 17.10 there is no Firefox 56 package so try the 17.04 packages. For other versions try the closest newer package, or the closest older package if that one fails.

Once you've downloaded the correct package, you'll have a .deb file. Install this with sudo dpkg --install. So for example if you downloaded the 17.04 64-bit package, the command would be sudo dpkg --install firefox_56.0+build6-0ubuntu0.17.04.2_amd64.deb. Replace the filename in the command with the one matching the package that you downloaded.

You'll probably see some errors after running the dpkg command. This is normal. Run sudo apt-get -f install to fix the errors by installing/updating the required dependencies.

You may need to run sudo apt-mark hold firefox before running sudo apt-get -f install, personally I've never needed to do this but the other answers imply that this is necessary. Probably no harm done by using this command, and it will prevent Firefox from being updated automatically (use sudo apt-mark unhold firefox to allow Firefox to be updated again).

EDIT: These packages seem to have been removed. An updated version is available, using the same package for all supported Ubuntu versions:

• 32-bit
• 64-bit

Answer 5

You don't have to downgrade to 56 to use legacy extensions.

You can install the "Firefox Nightly" version which allows you to enable legacy extensions on 57+. Currently, I am using version 59* and legacy extensions work just fine for me so far.

First, install the ubuntu-mozilla-daily ppa by running the following commands:

sudo add-apt-repository ppa:ubuntu-mozilla-daily/ppa
sudo apt-get update

Next, run the following command install Firefox Nightly:

sudo apt install firefox-trunk

Additionally, if you want to use your current Firefox profile, run the following command to copy your existing Firefox profile to the Nightly build:

cp -R $HOME/.mozilla/firefox/* $HOME/.mozilla/firefox-trunk/

Finally:

• open Firefox Nightly and go to about:config

• search for extensions.legacy.enabled

• double-click extensions.legacy.enabled to toggle the value to true

• search for extensions.allow-non-mpc-extensions

• double-click extensions.allow-non-mpc-extensions to toggle the value to true

---

Note: most of my non-multi-process-capable extensions do not work.

Answer 6

An upstream Firefox release, or even multiple such releases, can be installed alongside the ubuntu-maintained version, as suggested in answers to this question on Unix and Linux SE.

You could then use these old versions just when you want to use the apps that need them, and disable the autoupdate in their settings.

This is the best way to deal with legacy web apps in times where browser-makers think of 10 year product lifetimes or backwards-compatibility as four letter words.