You can open this bookmarks HTML backup in a Firefox tab (File -> Open File) to see if there is a problem with the file.

What is the file size of this file?

Yes, I can open the file in a tab in the browser. I'm not sure how I would find a problem this way, unless it wouldn't open.

The size of the file is 252 kb.

Do you see all the bookmarks in the file?

The file does has a .html file extension?

Yes, it appears to be a complete list and it does have an HTML extension.

Please try this : uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files , C:\Program Files(x86) & C:\ProgramData Then restart system. Then run Windows Disk Cleanup. (Note: This should be Pinned and run Weekly, If never done below expect 10's of gig's) Then run it again and click the button that says Cleanup System Files. Note: your Firefox Profile is saved. But you should make a back up before you do :

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer

Reinstall with Current Release Firefox 60.0.2 with a Full Version Installer

• https://www.mozilla.org/firefox/all/

Then now try to import your bookmarks .

Please let us know if this solved your issue or if need further assistance.

Hi n9wys, I'll mention two other possible workarounds:

(A) Importing Internet Explorer Favorites into Firefox bookmarks

You can import the HTML file into IE 11 (it's on the File menu, tap the Alt key to show the menu bar if needed). IE will convert the file contents to Windows Favorites. Note: not tested with Edge.

Then: Import Bookmarks and other data from Microsoft Edge

(B) Importing bookmarks from Google Chrome

If you have Chrome installed, similar idea. See: Import bookmarks and other data from Google Chrome.

If you use Sync then best is to disconnect Sync temporarily during troubleshooting.

You can check for problems with the places.sqlite database (bookmarks and history) in the Firefox profile folder.

• use "Verify Integrity" on the "Help -> Troubleshooting Information" (about:support) page

See also:

• http://kb.mozillazine.org/Locked_or_damaged_places.sqlite
• https://support.mozilla.org/en-US/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file

If "Verify Integrity" on the "Help -> Troubleshooting Information" (about:support) page cannot repair places.sqlite then remove all places.sqlite files in the Firefox profile folder. Firefox will rebuild places.sqlite and restore the bookmarks from a recent JSON backup in the bookmarkbackups folder.

• keep a backup copy of places.sqlite in case a new places.sqlite database has to be created
• http://kb.mozillazine.org/Unable_to_process_the_backup_file_-_Firefox

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

I did as jscher2000 suggested, and imported the bookmarks into IE11 - then exported that file and imported them into Firefox. This worked, and all is well again.

THANK YOU!!