http://kb.mozillazine.org/Unable_to_process_the_backup_file_-_Firefox

jscher2000 has a tool on his website to extract out your bookmarks and save them to an HTML-format bookmark export file. If you want to try it, here is the page:

https://www.jeffersonscher.com/res/bookbackreader.html

To open the bookmarkbackups folder in Finder, use the "Open in Finder" button in the first table on the Troubleshooting Information page, and double-click into bookmarkbackups where you should see several dated files. From there you can drag and drop onto the conversion tool.

To import the HTML file, see the steps in this article: Import Bookmarks from an HTML file.

Sometimes the bookmarks backup files get corrupted.

Every now and then, Open the Bookmarks Manager; Press the Alt or F10 key to bring up the toolbar, and select Bookmarks. Hot key is <Control> (Mac=<Command>) <Shift> B.

Once the window is open, at the top of the page, press the button labeled Import and Backup. Select Export Bookmarks To HTML, and follow the prompts and save it to a HTML file.

If you want, you can Copy the file to another computer/profile. Repeat the instructions above, BUT select Import Bookmarks From HTML.

https://support.mozilla.org/en-US/kb/restore-bookmarks-from-backup-or-move-them

https://support.mozilla.org/en-US/kb/recover-lost-or-missing-bookmarks

The tool FredMcD said

http://kb.mozillazine.org/Unable_to_process_the_backup_file_-_Firefox jscher2000 has a tool on his website to extract out your bookmarks and save them to an HTML-format bookmark export file. If you want to try it, here is the page: https://www.jeffersonscher.com/res/bookbackreader.html To open the bookmarkbackups folder in Finder, use the "Open in Finder" button in the first table on the Troubleshooting Information page, and double-click into bookmarkbackups where you should see several dated files. From there you can drag and drop onto the conversion tool. To import the HTML file, see the steps in this article: Import Bookmarks from an HTML file.

Thanks for your advice.

The tool you suggested successfully recovered my Bookmarks from the backup file and enabled me to turn them into an HTML file.

I've also used the tool to run a repair on the original backup file, from which I've made a new JSON file.

From these files, I've tried to recover the Bookmarks into Firefox but unfortunately I still hit the same error with the JSON file, and when the HTML file is used, nothing is imported. This suggests my version of Firefox may also have become corrupted.

I'm going to do a reinstall and then try to re-import the files.

Let’s do a full clean re-install;

Download Firefox For All languages And Systems {web link}

Save the file. Then Close Firefox.

Using your file browser, open the Programs Folder on your computer.

Windows: C:\Program Files C:\Program Files (x86) Note: Check Both Folders

Mac: Open the "Applications" folder. https://support.mozilla.org/en-US/kb/how-download-and-install-firefox-mac

Linux: Check your user manual. If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it. See Install Firefox on Linux; https://support.mozilla.org/en-US/kb/install-firefox-linux

If you downloaded and installed the binary package from the Firefox download page, simply remove the folder Firefox in your home directory. http://www.mozilla.org/firefox#desktop ++++++++++++++++++++++++++++ Look for, and remove any Mozilla or Firefox program folders. Do not remove the Mozilla Thunderbird folder if there is one.

Do Not remove any profile folders.

After rebooting the computer, run a registry scanner if you have one. Then run the installer. +++++++++++++++++++++++++++ If there is a problem, start your Computer in safe mode and try again.

http://encyclopedia2.thefreedictionary.com/Linux+Safe+Mode This shows how to Start all Computers in Safe Mode; Free Online Encyclopedia

If there is still a problem importing the bookmarks,

Type about:support<enter> in the address bar.

Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox.

Locate the places.sqlite . Then rename or delete it. Restart Firefox.

places.sqlite : History and Bookmarks.

If the bookmarks still will not import, open the Bookmarks Manager and import the HTML file.

FredMcD said

If there is still a problem importing the bookmarks, Type about:support<enter> in the address bar. Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox. Locate the places.sqlite . Then rename or delete it. Restart Firefox. places.sqlite : History and Bookmarks. If the bookmarks still will not import, open the Bookmarks Manager and import the HTML file.

You, my friend, are a genius and I thank you for your help. Firefox is now reinstalled and my Bookmarks have been fully restored.

Thank you.

I did the Firefox Refresh suggested to address ongoing issues with slowness and flaky behavior which have become more and more prevalent of late. I had the same result as the original poster and the restore bookmarks function returned the same "unable to process backup file" message.

Thankfully I was able to stumble onto this question and while some of the answers were beyond me, I did try the one suggested to find and rename the places: sqlite file. Upon restarting Firefox it did allow me to restore an old bookmarks backup.

There is no way that something intended to solve problems (the "refresh" of the browser) should lead to even more thorny problems. I am not a techie nor a hobbyist; I just want something that works. More and more often of late, Firefox does not work properly. Troubleshooting to this extent should not be necessary. I am very disappointed with the path Firefox is on of late.

Back up and restore information in Firefox profiles.{web link} I use an add-on that makes backups of my user profile, Just In Case. Unfortunately, it is not compatible with the current Firefox.

Every now and then, open the profile folder and create a copy of the current profile as is to another location on your hard drive. This way you will have a backup.

If you do this each day, you will not lose much data. This should be done with Firefox Closed.

Note: In case you need to restore from these backups, you may need to overwrite old or corrupted files.

Or, and more likely, I could just switch to Chrome, despite my dislike for Google. Really, how hard can it be to make a browser that just works dependably without need for such gymnastics? Firefox used to be that way which is why I have used it forever. But now they have added so many useless (to me) or largely unwanted features to it, and push out apparently untested releases so often, that it acts like it's held together with chewing gum and duct tape. I long for the days early in this decade when FF was a stable, dependable browser.