You need to update to Firefox 61. Add-ons not withstanding. There is no add-on that provides functionality worth te major security issues involved with running old versions of Firefox.

You can find some alternatives to your add-ons:

• https://addons.mozilla.org/firefox/addon/bookmark-tab-here/ as an alternative to Add Bookmark Here ^2
• https://addons.mozilla.org/firefox/addon/all-tabs-helper/ will run in Firefox 61, you just need to update it
• https://addons.mozilla.org/firefox/addon/bulk-media-downloader/ as a replacement to Flashgot
• https://addons.mozilla.org/firefox/addon/tab-session-manager/ as replacement to Session Manager

You can use https://mozilla.github.io/extension-finder/ as a way to find replacements for out of date extensions. This should help, but regardless, you need to update.

Thank you for responding. I will check out the add-ons you recommend.

But in the mean time I would still like to know if Firefox can be stopped from updating by replacing the program "updater.exe" with a program that does nothing.

Thanks again.

 -- dogtac

I would strongly suggest not messing around with the internals of Firefox, not updating it is a bad idea overall. Why don't you update, install those replacement add-ons and keep it up to date in the future

Thanks for the quick response. As I said in my original post, the reason I will not be updating Firefox is because it's not worth using without these add-ons. I will check out the add-ons you suggested, but I have looked before and failed to find suitable replacements.

Why don't you consider providing legacy support for these older add-ons? When you cut off support for these you eliminated features that people had been using for years. This amounted to a substantial downgrade to the functionality of Firefox.

As far as messing around with internals, this is one of my joys in life. And since Mozilla publishes the source online, I'm sure a solution is there to be found.

  Thanks again for you suggestions.

  -- dogtac

https://www.howtogeek.com/333230/why-firefox-had-to-kill-your-favorite-extension/

Support was dropped because we could not continue to support the old style extensions, and move forward with a modern web browser. The old extensions had access to literally everything in the browser, and it was getting so bad that we couldn't continue to innovate with that system.

So a new, modern system called Webextensions was created, that gives Add-ons unchanging API's for accessing functions of Firefox. This not only makes Firefox faster and more secure, it gives add-on makers the peace of mind that they can create an add-on, and it will not break everytime Firefox updates, starting with 57. We are continually adding new API's.

Please update to 60.0.1 ASAP, and then find replacements. But none of those add-ons are things that can't be replaced.

Thanks to Pkshadow for the excellent link and Tyler Downer for the explanation. I now see what is going on. I can't say I'm happy with it, but I see the necessity of it. I'm still not sure what I will do but it's clear that it will be a while before I settle on a suitable alternative to the old Firefox I knew and loved, RIP.

Sincere thanks to both of you for all your help and advice.

 -- dogtac

I am really, really tired of software companies that decide what's best for me; to make things even worse, they even forcefully prevent me from installing earlier versions by instantly updating the second an old version is executed.

I wish Mozilla would look at some of these forums and the number of complaints about this practice. They are forcing us to go instead to a different browser altogether!

I know that it may be safer to use the latest version, but if the program isn't convenient for me to use, I'm going to change! Please listen, Mozilla!