@muzi : you can use apt (or a GUI like Muon) to install an older version. Ex 'sudo apt-get install firefox=55.0.2+build1-0ubuntu0.16.04.1'
@muzi : you can use apt (or a GUI like Muon) to install an older version. Ex 'sudo apt-get install firefox= 55.0.2+ build1- 0ubuntu0. 16.04.1'