Starting with Firefox version 49, Firefox requires Mac OS X 10.9 (Mavericks) or higher. Visit this Apple Support page to find your Mac OS version.
Jan 29, 2021 BullGuard Internet Security packs a lot of features, including backup and performance tune-up, but the quality of features doesn't match the quantity. Safari 10 for OS X Yosemite and OS X El Capitan does not include all of the new features available in macOS Sierra, like Apple Pay on the web and picture-in-picture support for videos, but the. El capitan - setting default browser You’re now watching this thread and will receive emails when there’s activity. Click again to stop watching or visit your profile/homepage to manage your watched threads.
If you're using an outdated version of Firefox on Mac OS X 10.8 (Mountain Lion) or earlier, the only way you can update Firefox to a secure version is to upgrade your Mac OS to a version that Apple supports. Visit this Apple Support page to learn more about upgrading your Mac.
While insecure versions of Firefox will continue to work on OS X 10.8 and earlier, using an up-to-date version of Firefox on a supported version of Mac OS will provide you with the best and safest user experience.