I'm an idiot. I ran a new version of Firefox nightly without creating a new profile. When I went to run my regular Firfox, I got this error message:
Here's how I fixed it.
- Close down Firefox
- Open a terminal and run:
- Let Firefox start up and create a new profile. Then go to:
- You'll see something like this:
- Select "Set as default profile" and click through any warnings
- Close Firefox.
- Once again, run
That should do it! Next time you start Firefox normally, everything should be fine. Probably.
In the future, make backups of your
$HOME directory, and create a new profile for your Nightlies!