Fonts not embedding in Gumbo?
You've embedded your font via DefineFont4 in Gumbo using either CSS or ActionScript, but, try as you might, the embedded font is not showing up in your project. If you were migrating a Flex 3 project in Flex Builder to Gumbo and you were previously embedding fonts, check your project settings and look under compiler flags to see if you find the following flag:
If you do, remove it! That's the culprit right there! :)
Otherwise, check that you're doing everything correctly -- your embed code should look something like this: