By any chance, did you check whether your Firefox started up in the wrong profile? The following article has those steps first: Recover lost or missing Bookmarks.

Assuming that is not the issue, it's possible that Firefox is not able to access the database file that stores your bookmarks. This will cause Restore to fail as well, and make it impossible to save new bookmarks. For that problem:

First, if you haven't already, please do a normal shutdown and/or restart of your system. Restarting Windows can help by freeing up locked files, completing any deferred updates, and resolving temporary file permission issues.

Next, if Firefox still has bookmark problems, could you let us know what you get when you run the "Verify Integrity" diagnosis and repair function. That's here:

Open Firefox's Troubleshooting Information page using any of these methods:

• "3-bar" menu button > Help > More Troubleshooting Information
• (menu bar) Help > More Troubleshooting Information
• type or paste about:support in the address bar and press Enter

Near the bottom, there is a section titled Places Database -- that's the file which stores history and bookmarks. Click the button labeled Verify Integrity. There may be a 10-15 second delay before results appear.

If all is well, the report that appears below the button should start with:

> Task: checkIntegrity
+ The places.sqlite database is sane
+ The favicons.sqlite database is sane
> Task: invalidateCaches
+ The caches have been invalidated
> Task: checkCoherence
+ The database is coherent

Does yours say that, or something else? You can select and copy the report, and then paste it into a reply for review and comment.

Please see response below.

Places Database Integrity > Task: checkIntegrity - Unable to fix corruption, places.sqlite will be replaced on next startup > Task: checkCoherence - The task queue was cleared by an error in another task. > Task: expire - The task queue was cleared by an error in another task. > Task: vacuum - The task queue was cleared by an error in another task. > Task: stats - The task queue was cleared by an error in another task. > Task: _refreshUI - The task queue was cleared by an error in another task. Statistics

This line --

- Unable to fix corruption, places.sqlite will be replaced on next startup

-- means that the next time you exit Firefox and start it up again, Firefox will create a fresh database using the last automatic bookmark backup (but no history, since there's no backup for history).

Does that work?