Hi! I see you're having trouble logging in to Air France, and you get a "page not found" error on Firefox, Chrome, and Safari on your Mac running OS X 10.15. Just to get a better idea, is this issue happening when you try to log in on the Air France website, or is it in the Air France app? Also, are you getting the "page not found" error immediately after entering your login details, or right when you access the login page?

Meanwhile, here are some quick steps we can try:

1. Clear your browser cache and cookies for the Air France site. Sometimes outdated cache/cookies can cause loading errors.
2. Make sure your browsers are updated to the latest versions supported on macOS 10.15.
3. Check if cookies and JavaScript are enabled in your browsers, as they are needed for login functionality.
4. Try opening the Air France login page in an incognito/private window to bypass any interfering extensions or cached data.
5. Restart your Mac and try again, to rule out temporary network or system glitches.

If none of those work, it might help to check if there’s a temporary issue with Air France’s servers or website accessibility, as some users have recently reported login errors or "page not found" on the site.

Let me know if you’ve tried any of these or if you want me to guide you step-by-step through clearing cache or checking settings. We’ll get this sorted out!