It appears you are using the old EOL macOS 10.14.

In order to run Firefox 116.0 and later including the Fx 140.7.0esr and Fx 147.0.3 Release on macOS you need to update your macOS to 10.15 (ten.fifteen) at minimum.

the computer has automatically updated Firefox, most recently in January 2026. That may be the limit? Peacock requires 126 (or approximation) to opne an account. Any more suggestions are welcome. Thank you.

the computer has automatically updated Firefox, most recently in January 2026. That may be the limit? Peacock requires 126 (or approximation) to opne an account. Any more suggestions are welcome. Thank you.

I am saying you need to update your macOS first if your hardware allows it as it may be macOS 10.14 is the most current you can run on it.

Firefox 115 ESR is based on the old Firefox 115 Release but with stability and security fixes since. The Firefox 115.33.0esr out on Feb 24 will be the last planned update for the old Firefox 115 ESR channel.

https://support.mozilla.org/en-US/kb/firefox-users-macos-1012-1013-1014-moving-to-extended-support