Hello,

As I can see, all is working fine for me(on firefox). Is it a narrow box with two rows of two characters? Firefox displays that code when it cannot find the corresponding character in any available font. The most common reason to see this is that some sites are now replacing image icons with font characters that Firefox has to download. If you have set Firefox to:

   1. use only your preferred fonts instead of the page's preferred fonts
   2.  not download fonts (either in about:config or using the NoScript    extension) 

then you would need to change that in order to see the icons.

First check your font settings here:

"3-bar" menu button (or Tools menu) > Options > Content

Click the Advanced button and make sure there is a check in the box for "Allow pages to choose their own fonts".

If you change that, try reloading the page. Does Firefox load the missing icons?

If that doesn't fix the issue then do the following:

You can check the gfx.downloadable_fonts.enabled pref (which you say is true, still check again) on the about:config page (you can go to it by typing about:config in your address bar) and make sure that it is set to true (if necessary double-click the line to toggle its value).

Hope it helps.

If you open Google's test page for that font, does it seem to work normally there?

https://www.google.com/fonts/specimen/Lato

Oops, my bad, the icon font is on the site itself. Never mind.