Reinstall old firefox version
I recently downloaded the new version of Firefox and dragged it to the application folder. When it asked if I wanted to retain or replace the existing version I clicked replace. Then I found my computer is too old to run the new version. Can I still get and download the previous firefox browser version?
Alla svar (1)
Firefox 78.15.0 ESR is the last version for Mac OS X 10.9/10.10/10.11 and you will no longer receive updates.
Firefox 78.15.0 on the Mozilla CDN server:
Mac OS users on OS X 10.12/10.13/10.14 have been moved to the 115 ESR update channel since your macOS X 10.14 platform no longer is supported, current releases require macOS 10.15 as a minimum.