Web Fonts not working in some Firefox (including Google Fonts Sample Page)

Question

Firefox 21v, Windows 7 32Bit

We are about to use Google Fonts for an upcoming project. We've found two computers with Firefox which doesn't display any web fonts at all.(Chrome display them correctly) All our computers has Firefox 21.0 version. Seems it's something related to the OS or Firefox dependency. Is this known bug for Firefox? (Assuming the Google Fonts page has correct css rules for embeded font)

Answer 1

Replace the default protocol http:// with https:// - it worked for me.