Backup your bookmarks manually. If you have been using the "import" you may have already lost some information by overwriting it. As a matter of course you should always save current bookmarks manually before using any restores.

• Restore bookmarks from backup or move them to another computer

That way you can ensure you are able to restore the complete current set. Put your .json backup file somewhere safe outside Firefox program or profile paths. The Windows Desktop or removable media would be suitable.

Firefox does create some autobackups of bookmarks but does not do anything about backing up the History. Luckily Windows probably backs up previous versions of your file places.sqlite and that is the database with History and bookmarks in it. See if you can recover a recent version of that, it will restore your history up to the date of the restored file.

• http://windows.microsoft.com/en-US/windows7/Previous-versions-of-files-frequently-asked-questions
• the file places.sulite is in the Firefox profile, a hidden folder that is easy to find by using troubleshooting. see Profiles - Where Firefox stores your bookmarks, passwords and other user data_how-do-i-find-my-profile

Afterwards import your more recent bookmarks from wherever they were saved. The import overwrites the slightly older bookmarks from the Windows file.

You my also then wish to install and run the addon places maintenance.

• https://addons.mozilla.org/en-US/firefox/addon/places-maintenance/

That may be used to check and repair the places.sqlite database. It will give a short status report. Note if the places.sqlite runs out of space it starts deleting History.

In future you my wish to routinely create occasional backups of your profile or at least your places.sqlite

• Back up and restore information in Firefox profiles

Thank you John99. Very helpful. Now I know what to do in future.

What about your current bookmarks I tried to write a reply to help you get back the bookmarks that you had lost.

Did you

1. do the backups to preserve whatever info you have
2. try following all the instructions and manage to recover bookmarks ?

Yes, I did the backups. As for the bookmarks, as I said in my original email, they were preserved for some reason.

Thank you and regards

Sorry just scim reading when I made the last reply.

The places files if you recover a previous version from Windows will include your history. Did you manage to recover that ?

If you did the file could be used and would include most of your History and you could then update your bookmarks from the backups.

Chances to recover a places.sqlite file without errors are very low because of if minimum file size of 10 MB and the file is a binary file, so you can't check or repair the file.