Hi mirandaholmes, it's hard to know whether the problem is in the backup or in the current Places database (the file which stores both bookmarks and history), or both.

Could you try to convert one of your backups and see whether that helps? Here's how:

Open your current Firefox settings (AKA Firefox profile) folder using either

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

In the first table on the page, on the Profile Folder row, click the "Show in Finder" button. If Finder highlights an icon with a semi-random name like a1b2c3d4.default, double-click it to display the contents of that profile folder.

Then double-click in to the bookmarkbackups folder. Here you should find files with dates coded into the names, such as:

bookmarks-2018-11-29_6240_gibberish==.jsonlz4

Resize this window so it's easy to see the Firefox window, then switch over to Firefox.

Open this tool on my website:

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

Drag and drop a backup file onto the white box on that page.

Hopefully there won't be an error message, and data will fill the box. You can try two different conversions:

(A) Clean the backup

Under JSON "Backup" Format click the Check/Repair button. Then click Save JSON and save the file in a convenient location. This is a file you could try restoring using the Restore feature, "Choose File..." option. It will replace existing bookmarks if it works.

(B) Convert to HTML Export

Under HTML "Export" Format click the Export HTML button and save the file in a convenient location. This is a file you could try importing using the steps in "Import Bookmarks from an HTML file." It will add to your existing bookmarks if it works, but they might be in a new "Imported Bookmarks" folder at the bottom of the Bookmarks Menu instead of in their original locations.

Do either of those work?

Thanks for the detailed instructions. Neither of these worked unfortunately. The first gave me the same error message, and the second didn't give me anything at all, no change whatsoever, even after closing the browser and opening again.

The html file is helpful to have though, as I can read it very clearly and try to fill in all the bookmarks by hand.

Is it possibly a bug, in this version of Firefox? Why would a perfectly readable html file not be importable? Should I try deleting Firefox, and installing it again?

I think most likely at this point is that the Places database is corrupted. Sometimes you can fix it using the "Verify Integrity" feature and sometimes you just need to start a new one. I don't know if there are any special considerations related to restoring a Time Machine backup, such as possible permission/privilege issues.

If you haven't already, could you try shutting down your Mac and restarting it to release any file locks?

Database Maintenance

You run this from the Troubleshooting Information page. Either:

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

Use Find (Command+f) to search for verify and Firefox should bring up the "Verify Integrity" button. After you click that, there's usually a delay of several seconds, and then Firefox starts reporting information about the database. You can copy/paste that into a reply for comment if you like.

New Database

If that didn't help, this article describes how to rename places.sqlite (or move it out of the profile folder) so that Firefox generates a new one. History is lost in this process.

Fix "The bookmarks and history system will not be functional" error message

Thanks! The first step worked, once I rebooted my computer. After that I was able to restore bookmarks from a backup file. Here is the output from "verify":

> Task: checkIntegrity - Unable to fix corruption, places.sqlite will be replaced on next startup > Task: invalidateCaches - The task queue was cleared by an error in another task. > 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: originFrecencyStats - 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.

"Unable to fix corruption, places.sqlite will be replaced on next startup" is a bit scary, but maybe that's what it took to get bookmarks working again.