Using FTE CFF Font in Flash: Class mx.core::FontAsset could not be found.

This happened when I was using a CFF font in a non-Flex project. I compiled my font and the Flex compiler will leave out FontAsset because it thinks the host SWF will have this class – well, not so if it’s not Flex. So, when compiling your font you have to tell the compiler to include any Flex classes in your font SWF:

-static-link-runtime-shared-libraries=true