hello robd, please check in firefox > options > advanced > network > connection - settings... if firefox is set up to directly connect to the internet ('no proxy').

Firefox can't load websites but other browsers can

Thanks for quick response. Solution worked and gmail is now working

I'm using Firefox 17.1.0, but there isn't : "firefox > options > advanced > network > connection - settings..." . I attach an image (catalan language). With oldest Firefox, I could change proxy settings without any problem.

Why is not that configuration now?

Thank you, Sergi.

hello, i've tried it with a fresh copy of a catalan firefox & it's showing up as expected for me...

please try if it's the same when you launch firefox in safemode once (then it might be an issue with an extension hiding this setting) or else try a reset of firefox.

Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

Refresh Firefox - reset add-ons and settings

Thanks a lot! i've used : Reset Firefox – easily fix most problems and with a reset Firefox to its default state, now it appears as usual.

Thanks again, Sergi.