I've followed the instructions for recovering lost bookmarks and it didn't work.
You may need to update firefox
To do this go to firefox button > Help > About Firefox > Check for updates
and then follow the instructions below.
For more information, see the Restore bookmarks from backup or move them to another computer article. For other solutions, see the Recover lost or missing Bookmarks article.
If this doesnt work(or hasnt) your places.sqlite may be messed up.
Please update to the current Firefox 22.0 release.
The Firefox 16 version that you currently run is no longer supported with security updates.
The Firefox updater only updates to version 20. I have done that. I have then tried to restore bookmarks from a known good date - no joy. Nothing happens.
Finally updated to version 22 but still no bookmarks. I've tried restoring from various dates when I know that the bookmarks were working but nothing happens.
The places.sqlite issue is above my ability. I've used firefox for many years and have loved it but I think I'm going to have to abandon it and go to IE. I don't really like doing that but I really need my bookmarks and losing them is a major blow!
Thank you for your efforts, however. I appreciate it.
There is detailed info here => http://kb.mozillazine.org/Locked_or_damaged_places
You can use this button to go to the Firefox profile folder: