Oh... you might have been on the "beta" track and received Firefox 49. You can still run either:

• Current release: Firefox 48
• Extended Support Release: Firefox 45 + security updates

For more information, please see: https://blog.mozilla.org/futurereleases/2016/04/29/update-on-firefox-support-for-os-x/

As a Windows user, I'm not the best person to explain how to switch between versions on a Mac. You might want to make a backup first: Back up and restore information in Firefox profiles.

Thanks for the link. It explains the reason but doesnt bring back my old faithful firefox. I appreciate your prompt response.

As I said, not a Mac user, so take this with a sense of caution:

(1) Back up your profile, which contains bookmarks, passwords, history, etc., just in case: Back up and restore information in Firefox profiles

(2) Uninstall (trash?) Firefox without removing your profile

(3) Install Firefox 48.0: How to download and install Firefox on Mac

Thanks for trying but my 1gb memory is inadequate for the 48.0. Apple obviously expect me to invest in a 2gb model. Afraid that will have to wait for the lottery win. Thanks again for your help.

You appear to have OSX 10.6.8 and not OSX 6.8

Firefox 49.0 requires OSX 10.9 or newer.

The current Firefox 48.0 Released on Aug 2nd still works on OSX 10.6.8 however once Firefox 49.0 is released the Firefox 48.0 is EOL so in order to still get security updates for Firefox you can use the Firefox 45 ESR branch.

ESR channel builds generally get eight updates as 45.8.0 esr will be out when Firefox 53.0 is released. The 45.8.0 esr will then be the last unless Mozilla extends support to help Mac OSX 10.6, 10.7, 10.8 users for a while longer.

See https://support.mozilla.org/en-US/kb/firefox-osx on your options.

Sorry. My typo. 10.6.8.it is. Have tried options suggested but decided that Apple is doing its best to force hardware upgrade so I have found another browser that works. No doubt Apple will try to sabotage that as well but I live to fight another day. Many thanks for all your interest.

lostman said

so I have found another browser that works.

You can still use Firefox as I mentioned the Firefox 45 ESR which works on OSX 0.6, 10.7, 10.8. James said

ESR channel builds generally get eight updates as 45.8.0 esr will be out when Firefox 53.0 is released. The 45.8.0 esr will then be the last unless Mozilla extends support to help Mac OSX 10.6, 10.7, 10.8 users for a while longer.

Why does the "ESR" track have a different revision number? Is this actually a "branch" from the old rev 45, so not related to 46,47,48 ?

I don't know how to choose between staying with rev 47 or 48.0, or moving to the ESR version. How do they differ?

The ESR refers to Extended Support Release and was made for Enterprise users in mind. It is based on a Release every seven versions since Firefox 10.0 as it was 10.0, 17.0, 24.0, 31.0, 38.0, and currently 45.0. The next major version will be based on Firefox 52.0 Release.

https://www.mozilla.org/firefox/organizations/faq/

The Firefox 45.0 ESR will still run on Mac OSX 10.6, 10.7, 10.8 with updates to 45.8.0 ESR unless support is extended however all versions from Fx 49.0 on including the 52.0 ESR will not run.

Firefox 48.0 will be EOL once Firefox 49.0 is released as 48 will not get anymore updates and will get more vulnerable over time if you choose to stay with 48.

Will the ESR track contain security updates beyond 48.0.x ?

Is the last rev usable with OSX 10.6.8 exactly 48.0, or are all of the 48.0.x series OK (right now the latest seems to be 48.0.1).

The other day, after reading this thread, I updated to 48.0.1 from 47.0 (??) and I'm getting kernal panics from the NVDA process so often that I can't run Firefox at all. I came to this thread due to the NVDA crashes starting up again. So I don't know if its actually a hardware problem, or the version of FireFox.

I see a rev number 47.0b9

I cannot determine if this is a pre-47.0 version, or a version between 47.0 and 47.01

It would be helpful if this article explained how the beta numbering works in that regard:

https://support.mozilla.org/en-US/kb/install-older-version-of-firefox

It would also be helpful if the UPDATE process at least asked if you want a copy of the .dmg file downloaded. (if not doing it by default).

Having the .dmg would facilitate going back to the previous rev, and testing addons when a new rev behaves badly.

VerizonSucks said

Will the ESR track contain security updates beyond 48.0.x ?

It will get selected security patches until sometime next year.

The other day, after reading this thread, I updated to 48.0.1 from 47.0 (??) and I'm getting kernal panics from the NVDA process so often that I can't run Firefox at all. I came to this thread due to the NVDA crashes starting up again. So I don't know if its actually a hardware problem, or the version of FireFox.

Try the ESR version.

I see a rev number 47.0b9
I cannot determine if this is a pre-47.0 version, or a version between 47.0 and 47.01

b = beta = pre-release

Also, for your security, please don't find installers randomly, use the archive: http://archive.mozilla.org/pub/firefox/releases/

There you can see the build dates on the files to help assess what is newer.

I start from the Mozilla page: https://support.mozilla.org/en-US/kb/install-older-version-of-firefox

Noticed that you can't simply download a .dmg file of an older rev. They are all sdk.tar.bz2 files. Why? The newest rev is always simple a .dmg file.

And unarchiving leaves me with an .skd folder. What do I do with it to install the app ???

You need to look further up where it says the linux, mac or Win folders and then you pick the language and download the file.

For example the en-US Firefox 48.0.2 for Mac is at http://archive.mozilla.org/pub/firefox/releases/48.0.2/mac/en-US/

If you want the Firefox 45 ESR then look at https://www.mozilla.org/firefox/organizations/all/ or the current 45.3.0esr in in http://archive.mozilla.org/pub/firefox/releases/45.3.0esr/mac/