YSK That Firefox Quantum is being released tomorrow, and it may break a lot of your addons. You can easily switch to the extended release update channel to give yourself a bit more time
Firefox is switching to a different type of addon system with the release of Firefox Quantum (57.0). While it will be more secure in some respects, the major downside is that a lot of widely used addons (such as Session Manager) are not compatible.
While you do eventually have to update to remain secure, Mozilla offers an update channel geared toward enterprise users, and switching to it will buy you a bit more time (you still get security fixes, it just doesn't get feature upgrades as quickly as the regular update channel). If we're lucky, the devs of our favorite addons will have figured out by then how to create new versions, or perhaps Mozilla will even have offered the APIs needed to replicate old behavior.
That said, switching to ESR is easy.
- Close Firefox
- Run a text editor such as notepad as an administrator (right click and run as admin)
- Open the channel-prefs.js file in your Firefox installation directory. By default this will be in C:\Program Files (x86)\Mozilla Firefox\defaults\pref\
- Change
pref("app.update.channel", "release");
to
pref("app.update.channel", "esr");
Save the file, open Firefox, go to Help>About, and you should see ESR listed as your update channel.