I’ve recently encountered an issue twice in the last few weeks where the font-face fonts on a website stopped working after a migration to a new hosting provider.
I used the nifty tool, Backup Buddy from iThemes, and all went well, except on the new server the embedded fonts weren’t rendering. :/
After many hours of searching, checking headers, and such, I bothered to look at the console output in Chrome and noticed that there was an error speaking to cross-domain issues specifically regarding the font files.
So what was the issue? In WordPress, you can set the WordPress Address and the Site Address separately. If one is www.somedomain.com and the other is somedomain.com (aka the sub-domain doesn’t match) then you’ll get this pesky error.
Hope that helps.