Separate Issue; Your System Details shows;

Installed Plug-ins

Shockwave Flash 23.0 r0 Shockwave Flash 24.0 r0
Having more than one version of a program may cause issues. You must remove the older programs. Then get the current full installer.

Flash: Grab the uninstaller from here: Uninstall Flash Player | Windows Uninstall Flash Player | Mac

Then reinstall the latest version.

Note: Windows users should download the active_x for Internet Explorer. and the plugin for Plugin-based browsers (like Firefox).

Note: Windows 8 and Windows 10 have built-in flash players and Adobe will cause a conflict. Install the plugin only. Not the active_x.

Flash Player Version: 24.0.0.194

https://get.adobe.com/flashplayer/ Direct link scans current system and browser Note: Other software is offered in the download. <Windows Only>

https://get.adobe.com/flashplayer/otherversions/ Step 1: Select Operating System Step 2: Select A Version (Firefox, Win IE . . . .) Note: Other software is offered in the download. <Windows Only>

See if there are updates for your graphics drivers https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

The file is not coded as such, but it stores data as if it were.

Open the Bookmarks Manager; Press the Alt or F10 key bring up the tool bar, 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. Copy the file to another computer. Repeat the instructions above, BUT select Import Bookmarks From HTML,

What file is this about that you want to backup?

You can use these files in the current Firefox profile folder to backup your personal data.

• bookmarks and history: places.sqlite
• bookmark backups: JSON backups in the bookmarkbackups folder
• SQLite files like cookies.sqlite (cookies) and formhistory.sqlite (saved form data)
• logins.json and key3.db (decryption key) for Passwords saved in the Password Manager
• cert8.db and possibly cert_override.txt for (intermediate) certificates stored in the Certificate Manager
• persdict.dat for words you added to the spelling checker dictionary
• permissions.sqlite for Permissions and possibly content-prefs.sqlite for other Site Preferences
• sessionstore.js for open tabs and pinned tabs and tab groups

Thanks Cor-el. It was the bookmarks backups json files.

I think FredMcD has given me the answer. I'll have to save them as HTML somewhere, and then maybe W10 File History won't think it is an encrypted file and skip it.

Thanks to you both, and thanks FredMcD for letting me know about the duplicate software on my system.

Glad to help. Safe Surfing.