The people who answer questions here, for the most part, are other Firefox users volunteering their time (like me), not Mozilla employees or Firefox developers.

If you want to leave feedback for Firefox developers, you can go to the Firefox Help menu and select Submit Feedback... or use this link. Your feedback gets collected by a team of people who read it and gather data about the most common issues.

Well, in case someone else wants to use Firefox offline: If you want to go back up one "folder" level, use two periods in front of the target file's name. Example: When I went from the west-1 folder to one of its subfolders named green, in order to get back to west-1, I had to change the target file's path from "c:\fam\west-1\west-william-david-fam.htm", to "..west-william-david-fam.htm".

FredMcD, thanks for your help to others.

Just like working in DOS

Glad to hear that your problem has been resolved. If you haven't already, *Please select the answer that solves the problem*. This will help other users with similar problems find the solution more easily. Thank you for contacting Mozilla Support.

Well, as was pointed out, I posed an inappropriate question. I naively expected friendly help, forgetting, the computing world is cold and heartless. Since no one could answer an inappropriate question, no one gets any points. You will, of course, delete this entire inappropriate thread.

Hi DonaldWestMagazine, when did you first notice this change? Was it in the minor security updates from Firefox 57.0.3 to 57.0.4 or was it in the major leap from Firefox 56.x to Firefox 57.x?

When you use an address with backslashes like this:

<a href="C:\folder\folder\parent\page.html">PAGE</a>

Firefox generally gives an error page. I get this in both Firefox 57 and Firefox 52esr:

The address wasn’t understood
Firefox doesn’t know how to open this address, because one of the following protocols (c) isn’t associated with any program or is not allowed in this context.

Is it possible you were previously using a legacy extension that allowed Firefox to read backslashes in links as regular slashes, such as Slashy? That particular extension wasn't updated for the new extension interface (available starting around Firefox 49 but mandatory in Firefox 57+), and I don't immediately see a replacement.

While a new extension would be most convenient, fixing all the links is another option. And I realize it would take some time. I think the "least effort" fix along those lines would be to preface the links with the file:/// protocol. In other words, do a global find and replace as follows:

href="C:\

to:

href="file:///C:\

and for scripts and embedded images:

src="C:\

to:

src="file:///C:\

When I test a local file, that works for me in both Firefox 57 and Firefox 52esr.

DonaldWestMagazine said

Well, as was pointed out, I posed an inappropriate question. I naively expected friendly help, forgetting, the computing world is cold and heartless. Since no one could answer an inappropriate question, no one gets any points. You will, of course, delete this entire inappropriate thread.

I don't see why this thread would be deleted, and I don't think your question was inappropriate. Just difficult.

jscher2000, thank you for the reply.

I only noticed this after the most recent minor update, but that may only mean that's when I next tried to use a link that changes folders.

Is this another html *improvement*, or is it unique to Firefox?

Many years ago, I tried to quit knowing *any* programming, but still today, I find it necessary to know much more than I want, just so I can use this stuff.

DonaldWestMagazine said

Is this another html *improvement*, or is it unique to Firefox?

Different browsers handle local links differently. Firefox often is the most strict.

As a workaround, you can use a script to repair the links to a format Firefox likes. You can apply the script to the page by clicking a button on your Bookmarks Toolbar or Bookmarks Menu -- a bookmarklet.

To install it, see this page:

https://www.jeffersonscher.com/res/sumomarklets.html#fileC

After installing, when viewing one of your pages, click the button to run the script.

For reference, this is the script:

var els=document.querySelectorAll('a[href^="C:\"], link[href^="C:\"]'); for (var i=0; i<els.length; i++) els[i].setAttribute('href', 'file:///'+els[i].getAttribute('href')); els=document.querySelectorAll('img[src^="C:\"], script[src^="C:\"]'); for (i=0; i<els.length; i++) els[i].setAttribute('src', 'file:///'+els[i].getAttribute('src'));

An extension or userscript could automate that for you, but it's getting late here...

See also: http://kb.mozillazine.org/Links_to_local_pages_do_not_work