Hi

What platform are you on ? In the question details it says Windows Vista, but Firefox 115 doesn't work on Vista.

Users on Windows XP and Vista have been moved to the Firefox 52 ESR version.

• https://support.mozilla.org/en-US/kb/end-support-windows-xp-and-vista

Firefox 116 and newer require Windows 10 as the minimum, users on Windows 7 and 8 and 8.1 have been moved to Firefox 115 ESR.

• https://support.mozilla.org/en-US/kb/firefox-users-windows-7-8-and-81-moving-extended-support

Also Firefox 115.34.0esr is the current version and not the old Fx 115.14.0esr released back on August 6, 2024.

You can download the current full offline setup of Firefox 115 ESR here https://www.firefox.com/download/all/desktop-esr/ as just make sure you select [Download ESR 115]

It appears you may be running Firefox in Windows Vista compatibility mode for some odd reason as normally Firefox 52.9.0esr was the last to run on Windows XP and Vista.

The Firefox UserAgent you used to post this thread appears to be Mozilla/5.0 (Windows NT 6.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/115.0 as NT 6.0 is Windows Vista.

If you are using Windows 10 or 11 then see https://www.minitool.com/news/how-to-run-a-program-in-compatibility-mode.html though if you are actually running Windows 7, 8, 8.1 then the compatibility mode is still similar.