Pretty much what the title says. My computer didn’t shut down correctly a couple of days ago, and now my bookmarks are empty. I also can’t bookmark anything new. Any ideas on how I can fix this?
Oh, and I blame the SDMB: This happening caused my to re-subscribe! 
Strange.
Firefox does create backups of your bookmarks.html file.
Be careful with the advice below, you can mess things up further.
Under Windows look in (replace the userName and uniqueString with what’s on your PC):
C:\Documents and Settings\UserName\Application Data\Mozilla\Firefox\Profiles\uniqueString.default
In that directory you’ll see bookmarks.html (this is the active bookmarks file). You’ll also see bookmarks.bak (this is the most recent back-up). I’d first look at the bookmarks.html and see what’s in it (double-click it and it should open in firefox as a regular html file). If it looks truly hosed, try renaming the bookmarks.bak file bookmarks.html.
Also, newer versions of firefox contain a folder bookmarkbackups which contain daily backups going back 5 days.
LarsenMTL
Also, there’s an extension called Bookmark Synchronizer, which is a wonderful little tool. It stores your bookmarks off-line somewhere, periodically updates them when you shutdown Firefox, and if you’re on another, different computer that has Firefox, you can sign in, and get YOUR bookmarks anywhere. If you work off of different computers, or just want to have your bookmarks backed up, this is the way to go.
Ugh. This happened to me and I pretty much gave up after I couldn’t find any help. I then reinstalled Firefox and I still couldn’t bookmark anything. It never did get fixed until I reinstalled windows to fix some other things.