Hi John,

Barring a more elegant solution, you could edit the .xhtml file that
Firefox redirects to when it reaches a net error (you can view this by
visiting the following "url" using firefox: *about:neterror?e=dnsNotFound*).

The accepted answer here
<https://superuser.com/questions/1792996/customize-file-not-found-page-in-firefox-114>
explains where to find that .xhtml file, inside the omni.ja archive.

I've attached a custom omni.ja archive you could inject, and examples of
how it displays now vs how it used to display. If you plan to use this,
please save a copy of the original omni.ja file that you need to overwrite!
 omni.ja
<https://drive.google.com/file/d/1aExDyrFxdE0svkRZELAA2Zg03PHXtnwo/view?usp=drive_web>
[image: Example.PNG]
[image: image.png]

Best of luck,
Kaleb A. (Langara LIT Student)

On Thu, Feb 8, 2024 at 1:10 PM Lolis, John <[log in to unmask]> wrote:

> Prithee, might one of you be able to point me in the right direction with
> regard to modifying a browser error message, specifically a DNS error/site
> not found message?
>
> Here's the rub... in an effort to prevent use of our OPACs as public access
> computers, I've modified their DNS settings so that they only look to
> themselves for DNS queries.  In their hosts file, I only added entries for
> our catalog, our website and our museum pass reservation site.
>
> So this effectively prevents access to all other sites (unless of course
> someone happens to know the IP address of another site).
>
> The problem is that the browser returns the DNS error/site not found
> message, and there are no browser controls to go back since it's in kiosk
> mode.  We have a label advising patrons to press ALT← to go back to the
> previous page, but what I'd like to do is use a hex editor to modify the
> default browser error to communicate the same thing.
>
> So my question is, does anyone know where I can find those messages so I
> can edit them?  I've searched all sorts of Firefox files to no avail so
> far.  I'm not completely averse to using a different browser, although my
> preference is to *not* use Chrome or Edge.
>
> I also realize that whatever string I replace the error message with, it
> must be the same length (this brings back memories of working at Prodigy
> and editing command.com in MS-DOS so that it would return Bad command, you
> idiot!!).
>
> hmmm... as I write this, now I'm thinking of utilizing a redirect page of
> some sort, one that displays advice to the patron, then returns to
> wherever.
>
> Thanks much!
>
> John Lolis
> Coordinator of Computer Systems
>
> 100 Martine Avenue
> White Plains, NY  10601
> tel: 1.914.422.1497
> fax: 1.914.422.1452
>
> https://whiteplainslibrary.org/
>
> *“I would rather have questions that can’t be answered than answers that
> can’t be questioned.”*
> — Richard Feynman
> <
> https://click.fourhourmail.com/5qure95xkf7hvvo93wh2/7qh7h8h05vr4zrtz/aHR0cHM6Ly9lbi53aWtpcGVkaWEub3JnL3dpa2kvUmljaGFyZF9GZXlubWFu
> >,
> theoretical physicist and recipient of the Nobel Prize in Physics in 1965
>