There's no "update" for that, it's a matter of learning a different method of saving a bookmark that bypasses the feature which identifies duplicate bookmarks.

There 5 ways to save a new Bookmark in Firefox:
1. {Ctrl + D}
2. Right-click and select Bookmark this Page.
3. Bookmarks > Bookmark this Page
4. Double-click the Star that is on the right side of the Location bar.
4a. (A single-click on the Star will save the new Bookmark to the Unsorted Bookmarks folder.)
This last method will allow duplcates to be saved.
5. Left-click and drag the website image (Favicon) in the URL bar (or on the active tab) into the Sidebar view of Bookmarks {Ctrl + B}
or to the Bookmarks menu bar item (the drop-down will open) and then onto the drop-down listing of your bookmarks and folder of bookmarks (folders will open)
or onto the Bookmarks Toolbar
- the new bookmark will be saved when you release the left mouse button

Firefox bookmarks have worked like this since Firefox 3.0 was released, back in June 2008. The Bookmarks Tags feature was introduced in Firefox 3.0 to allow the user to categorize their bookmarks more easily than saving the same bookmark into separate folders.

See also:

• Old Add Bookmark Behavior: https://addons.mozilla.org/firefox/addon/old-add-bookmark-behavior/

You can create a copy (use Copy and Paste) of the bookmark in the Bookmarks Manager (Library) or in the Bookmarks sidebar if you want more to bookmark the same URL more than once.

"There's no "update" for that," I had that feature on version 24 of Firefox on my notebook and my desktop. The latest update removed it. Looks like I a lot of searching for it again. It was so very useful. Thanks for your help. George