Try holding down the Shift key while starting to get into [[Diagnose Firefox issues using Troubleshoot Mode|Troubleshoot Mode]]. Reinstall the [[Troubleshoot and diagnose Firefox problems#w_check-for-issues-caused-by-corrupt-or-incomplete-visual-c-installation|Visual C++ Redistributable]].

Note that the user is on Mac OS. Try to start Firefox in <b>Troubleshoot Mode</b> to see if that works. *Mac: hold down the Options key while starting Firefox *https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode Try to reinstall Firefox in case something went wrong with updating and drag the current Firefox application to the Trash. *https://support.mozilla.org/en-US/kb/install-firefox-mac You can find the full installer of the current Firefox release (125.0.1) in all languages and all operating systems here: *https://www.mozilla.org/en-US/firefox/all/#product-desktop-release *https://www.mozilla.org/en-US/firefox/125.0.1/releasenotes/