Just doesn't work anymore for me (i use Nightly)

[TheVgam3r]

its been a few weeks since it just completely stopped working for me and idk why i'm waiting for the new version ig

[MrRollton]

Hi! I recently faced an issue where the sidebar tabs would not open when I click them. Installing the latest version and clearing the start-up cache fixed the issue. I'd advise to do the same and see if it helps.

[PrayagS]

It happens after an update for me. I'm on macOS.

It has to do with the files from fx-autoconfig (defaults and config.js) that need to be present in /Applications/Firefox.app/Contents/Resources (in case of macOS). Since updates can reset this folder, I need to copy these files again and then clear the startup cache to make things work again.

The files that you copy in your profile directory remain intact though.