I've been getting access denied from more websites

Bonjour

For information Firefox release calendar https://whattrainisitnow.com/calendar https://whattrainisitnow.com/release/?version=esr

To complement, a similar discussion thread https://support.mozilla.org/en-US/questions/1607450

Firefox 115 Sorry, you have been blocked.

A test, just to see.

Below, an experience with Responsive Design Mode https://firefox-source-docs.mozilla.org/devtools-user/responsive_design_mode User Agent String

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:157.0) Gecko/20100101 Firefox/157.0

What is my User Agent? https://www.whatismybrowser.com/detect/what-is-my-user-agent

Yes, if you're able to upgrade to Monterey I'd absolutely recommend planning on doing that in the not–so–long–term, as the security support for your current legacy Firefox will end in less than six months — whereas updating your macOS will give you compatibility with the current releases and support for years to come.

Thank you for helping me understand the access issue. So why am I having access issues if Mojave is supported for six more months? When Firefox offers me updates now, are they not really updating? Will I still have access issues if I upgrade to Monterey?

Best regards

Firefox 115.0 ESR is based on the old Firefox 115.0 Release (July 4, 2023) but with security/stability fixes since. Many websites may be updated to work with more current versions of Firefox and not work so well with older versions.

The last planned update for the older Firefox 115 ESR channel is in March 2027 unless Mozilla decides to extend updates yet again. At least Mozilla is still supporting the EOL Windows 7, 8, 8.1 and macOS 10.12, 10.13, 10.14 for a while still as Chrome/Chromium based browsers dropped support way back in Jan/Feb 2023.

If your hardware allows for a macOS update to macOS 10.15 (ten.fifteen) or later then you would be able to run Firefox 116.0 or later including the current Fx 157.0 Release and current FX 153.4.0 ESR.

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

You're only getting security updates now, otherwise running a feature set from more than two years ago: Firefox users on macOS 10.12, 10.13 and 10.14 moving to Extended Support Release

The sites apparently require platform feature updates to operate.

(Or, honestly, they don't mostly require them, they only think they do and put roadblocks in — you might try the user agent switcher addon mentioned e.g. in support.mozilla.org/questions/1585074 to see if that resolves some of the existing blocks for you currently.)

Eventually on macOS 12 you'll be offered Firefox updates to catch up to the current feature set, and similar security blocks should disappear.