FontAwesome appears as question marks in FrameMaker 12. I installed the font in the Windows/Fonts folder. Do I need to do something else to get it to work in FM?

Well, if it's any consolation, it does the ????? thing (complete with bad font metrics for the question marks) in FM9, too.

I'm tempted to blame the font, but it could also be that FM is confused by things that shouldn't be where they are. You'll notice that some of the glyphs aren't given descriptive names in Character Palette.

For example, code points U+0000 through U+001F. Those are supposed to be the C0 Controls in Unicode, and not displayable glyphs.
http://www.unicode.org/charts/PDF/U0000.pdf

Ditto for U+0080 through U+009F, which are the C1 Controls:
http://www.unicode.org/charts/PDF/U0080.pdf

The glyphs at these code points should either be in standard Unicode positions (where the glyph is covered by Unicode, such as that left pointing triangle at U+0011, which might have been the same thing as defined by Unicode at U+25C0 or 23F4) or in some Private Use area.

Ask for your money back .