FireFox does not support certain web sites.

[weedtech]

If you go to www.regions.com you get an error and Firefox reports "Internal Server Error". But if you access this web page on other browsers like Chrome, the page loads just fine. This has been going on for over a year now.

[siffemcon]

No problem here. See https://askleo.com/internal-server-error/. Have you contacted the webmaster?

[weedtech]

Yes I have contacted them but their answer is that since the other browsers such as Chrome have no problem loading their page, it must be a problem with Firefox. I've tried using Firefox in "Troubleshoot Mode" and it still does the same thing.

[siffemcon]

You could file a compatibility issue via the 'Report broken site' option in the FF menu or at https://webcompat.com/issues/new.