See:

• https://support.mozilla.org/en-US/kb/fix-bookmarks-and-history-will-not-be-functional

What did you try from this article?

This usually means that Firefox has a problem with accessing places.sqlite. This can be security software or there are other problems with accessing this file.

Boot the computer in Windows Safe mode with network support to see if that has effect in case security software is causing problems.

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/
• http://www.7tutorials.com/4-ways-boot-safe-mode-windows-10

You can 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

You can create a new profile to test if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

I had tried those before without any success. When starting up Windows 10 and Firefox, the error message would appear on the initial Firefox page and there would be a n additional info link to that article.

I had tried restoring Firefox backed up info ( bookmarks I think) as well without success. I can see information in the Fire Fox files but I wonder if these files are corrupted and won't update. The places database was recreated as per the article but didn't help.

Sorry. I didn't see the last part of your response that relates to creating a new profile. I will do that possibly tomorrow and then update this.

I created another profile and I copied the previous places.sqlite file to the new profile's folder. Firefox using the new profile no longer has the error message and I can now see my history and bookmarks.

In a couple of days when I have more time I will check out the new profile in more detail. eg decide if there are other files that I should copy over (like some of the backup folders)

I think this item can be closed. Thanks for your quick responses.