Mac OS X 10.10.5 (Yosemite) is an older Apple operating system. Finding software that still works on it can be challenging. Many modern web browsers no longer support this version, leaving users vulnerable to security risks and broken websites.
If prompted to replace an existing version, select "Replace" to ensure the older, compatible version is installed. : firefox download for mac 10105 upd
: Click on the file named Firefox 78.15.0esr.dmg to begin downloading the disk image directly to your Mac. Mac OS X 10
While installing Firefox 78.15.0esr restores basic web browsing capabilities, running an un-updated browser on a legacy platform carries distinct challenges: select "Replace" to ensure the older