Those missing icons are actually supplied by a font that is downloaded from the server (@font-face) as you can see by the little boxes that show the hex code of the characters.

You can check the gfx.downloadable_fonts.enabled pref on the about:config page and make sure that it is set to true (if necessary double-click the line to toggle its value).

Make sure that you allow pages to choose their own fonts.

• Tools > Options > Content : Fonts & Colors > Advanced: [X] "Allow pages to choose their own fonts, instead of my selections above"

Thank you for responding cor-el. I've checked the gfx.downloadable_fonts.enabled, and it's value is indeed set to true. And the same can be said about the second solution, I looked there, and it's already set as you said, but the problem persists. It's annoying, but I think I may get used to it. I thank you for taking the time to answer, and I hope you contact me whenever another solution appears. :) Have a good time!!!

OK, I tested this and this looks like a CORS issue with the FontAwesome font not getting loaded.

The Web Console (Firefox/Tools > Web Developer) shows these errors:

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at http://d1d4324mp0stc8.cloudfront.net/s/ec6f202e/bb0864f0d2462d32150451462ed909d5bb98f134/static/dist/fonts/fontawesome-webfont.woff?v=4.1.0. This can be fixed by moving the resource to the same domain or enabling CORS. fontawesome-webfont.woff

downloadable font: download failed (font-family: "FontAwesome" style:normal weight:normal stretch:normal src index:1): bad URI or cross-site access not allowed
source: http://d1d4324mp0stc8.cloudfront.net/s/ec6f202e/bb0864f0d2462d32150451462ed909d5bb98f134/static/dist/fonts/fontawesome-webfont.woff?v=4.1.0 jarvis-lib.eb2c8ead.min.css

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at http://d1d4324mp0stc8.cloudfront.net/s/ec6f202e/bb0864f0d2462d32150451462ed909d5bb98f134/static/dist/fonts/fontawesome-webfont.ttf?v=4.1.0. This can be fixed by moving the resource to the same domain or enabling CORS. fontawesome-webfont.ttf

downloadable font: download failed (font-family: "FontAwesome" style:normal weight:normal stretch:normal src index:2): bad URI or cross-site access not allowed
source: http://d1d4324mp0stc8.cloudfront.net/s/ec6f202e/bb0864f0d2462d32150451462ed909d5bb98f134/static/dist/fonts/fontawesome-webfont.ttf?v=4.1.0

There is a workaround possible to see these icon font images, but this is not recommended as this involves disabling security features that would make you vulnerable.

I see... Thank you again, I tried before to download FontAwesome, but I didn't found out how to install them, that doesn't work like any ordinary font installing (copying the .ttf files into fonts directory), I also attempted some kind of "import" stuff in the web console for the .css files, but it didn't work either. I think it's better not to mess up with similar security features, for I'm not expert enough for doing so!!! I though about those pop-up downloading fonts that show up when opening some web-pages, but it's not the case with that one, it never required me to install any kind of fonts before!!! Problems with fonts or unicodes never presented to me when I was on XP, now so many are occurring when I upgraded to Windows 7, (fonts I installed but didn't work and so on...) Thank you anyways, I really appreciate your assistance cor-el!!! :D

Hi!!! :D The issue of the disappearing glyphs had been magically solved by itself. I think it source was from the web site, and now they've got everything right!!! Thank you cor-el for the time you took to look for a solution concerning it!!! Have a good day!!! :)

Yes, they seem to have fixed this partly. The web console no longer shows an error for the fontawesome-webfont.ttf font and a check confirms that the server sends an HTTP access control header, so at least that font works. The fonts/fontawesome-webfont.woff is still rejected and shows size 0 in the web console.

• http://d1d4324mp0stc8.cloudfront.net/s/ec6f202e/bb0864f0d2462d32150451462ed909d5bb98f134/static/dist/fonts/fontawesome-webfont.ttf?v=4.1.0

Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET
Access-Control-Max-Age: 3000

• https://developer.mozilla.org/HTTP_access_control