Why can't I install firefox 52 onto Mac OS X 10.8?
It is known that if one gives a tweak to the info.plist file, Firefox 52 will run on Mac OSX 10.8. Why is the minimum version set to 10.9? Is there any serious issue running this verion on older systems?
Opaite Mbohovái (2)
Firefox is not compiled to run on unsupported systems. Can you not update your MacOS? There's a pretty high chance you can at least install El Capitan, which is free, more secure and probably faster. https://support.apple.com/en-us/HT206886
Then you can run Firefox 67
Are you referring to this MacRumors forum thread?
Moambuepyre