I could'nt play Netflix or Amazon videos on my Firefox browser, I have an old MacBook pro OS 10.9.5 (it's the last operating system I can use.. I have photoshop 6 and it won't work on any further OSs) I went to update Firefox, was not sure what version it was. and my computer asked" replace current version of Firefox with New" , I said yes, it did.. and then after I downloaded it, I noticed there was a circle with a slash going thru it on Firefox Icon, when I tried to open new firefox , it bascically said will not work with this OS. I could not go back and lost firefox alltogher, which also had my prefernces and autofill passwords etc. I went to Mozilla site to see if I could find an older version of firefox.. This is what I found : Firefox version 78 was the last supported Firefox version for Mac users of OS X 10.9 Mavericks, OS X 10.10 Yosemite and OS X 10.11 El Capitan. These users were moved to the Firefox Extended Support Release (ESR) channel by an application update.

I downloaded it and it said It will not work on my OS, So, How can I basically get the same firefox I had or whatever the last version that works on my computer..and best case senario save my prefernces and passwords, which maybe might have been saved somehow when I tried to change in the begining .. thanks so much for your help.