''Tweedboy [[#question-1248187|said]]'' <blockquote> I have a "late 2008" macbook. I cannot upgrade this machine to mac 10.9 or later. How can I continue to operate Firefox? </blockquote> Hello Tweedboy, If it's impossible for you to upgrade your system, instead of using Firefox version 48.0, you could use Firefox version 45.9.0esr : http://ftp.mozilla.org/pub/firefox/releases/45.9.0esr/mac/en-US/ You'll probably already know everything that's mentioned in this article, but I'm giving you this link anyway : https://support.mozilla.org/en-US/kb/firefox-osx