Mozilla updates Firefox to a new major version every 6 weeks. The current version is Firefox 44. You can try the current version to see whether it works on that site:

https://www.mozilla.org/firefox/new/

Regarding the text message, that will still come through your mobile device associated with that phone number, using its default text messaging application.

Same problem occurred, here is the explanation:

The requested page "/en/exitnotice.php?token=b3d79956e5250d44470b3079869e1665&arg=http://www.firefox.com" could not be found.

Where does that message come from? What site or what program?

jscher2000 said

Where does that message come from? What site or what program?

I receive the text from my bank with the security code, that allows me to sign in, after I log out it gives me these options:

Video Demonstration Browser Requirements New Consumer & Small Business Online Services Terms & Conditions

Mozilla Firefox

   Version 40 is supported on Windows 7® and Windows 8®.
   Version 40 is supported on Mac OS X 10.10.4 "Yosemite".
   Version 20.0 is supported on Galaxy 10.1" devices.
   Download from www.firefox.com

WHEN I CLICK ON THE ABOVE, I GET THIS MESSAGE:

The requested page "/en/exitnotice.php?token=b3d79956e5250d44470b3079869e1665&arg=http://www.firefox.com" could not be found.

Okay, they have a broken tracking script attached to their link. Don't use their link, use the one I gave earlier:

https://www.mozilla.org/firefox/new/