Firefox stores your bookmarks and browsing history in the "Places database" file (places.sqlite), located in the profile folder. If the places database is damaged or if Firefox is unable to access the file for other reasons, many functions will not work. Symptoms include bookmarks disappearing or not saving, browsing history not saving and toolbar buttons such as Back and Forward not working. If you are having these problems, try the solutions listed below.
A previous Firefox session may not have closed properly or another program may be accessing your places.sqlite file, thus locking it. Exit Firefox and any other program you suspect may be interfering with your web browsing (or restart the computer) and then reopen Firefox.
For more information on troubleshooting extensions, see Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems.
A component installed with Norton 360 can cause problems with bookmarks and history after installing or updating to Firefox 3. These symptoms are caused by Firefox not completely exiting with the Norton 360 component enabled. If you are experiencing these problems, first update Norton 360 to see if that resolves the issue:
Symantec recently released a patch for Norton 360 that should address this issue for some users. Update Norton 360 by following the steps below:
If bookmarks history and toolbar buttons are working normally, you are finished. If you are still experiencing these symptoms, check for and disable incompatible extensions (see above).
Alternatively, you can disable Phishing Protection in Norton's settings and then restart the computer.
Another option is to follow the instructions below to manually remove the Norton component from Firefox.
If disabling extensions did not work or if you need to use extensions that are not compatible with Norton 360, you will need to remove a component that Norton 360 added to Firefox.
If these steps do not fix the problem, try following the procedures listed on the Configure Norton 360 to work with Firefox article.
You can also fix this by forcing Firefox to rebuild the Places database, as follows:
Firefox will create a new places.sqlite file and automatically import the most recent bookmark backup file. If no JSON backup is found, Firefox will automatically import your bookmarks from the profile folder bookmarks.html file, if it exists.