My computer is OS X Yosemite version 10.10.5. I have updated with the newest Firefox web browser today. Now I can't open Firefox because my computer is too old for this new version. Because I have totally replaced my old one with this new, I cannot go back.. And actually, I don't know what is the right version for my computer. I think I found some very long list of old versions(https://ftp.mozilla.org/pub/firefox/releases/), I don't know which one is right for me and how to install from there - I tried some of them.. If anyone can post the link of right one for my computer and inform me how to install it from there, I'd really appreciate it.. Than you.