It’s pretty commonly known that one of the ways to make Flash take forever to compile a swf is to embed every single glyph of a font, so that’s generally something to avoid. However, I seem to have encountered a situation where this has happened to me without my intending it.
One of the nice new features in Flash CS5 is the font embedding dialogue box. It’s now a global setting, so you can just change the set of glyphs you want to embed in one place, and it’s accessible through the Library panel:
Another nice thing you may notice is that the setting for ‘all glyphs’ is smart: it recognizes that this font doesn’t have 95,000+ glyphs, and so I can be kind of lazy and just check ‘all’ and let it embed a couple hundred glyphs. Nice and easy.
The problem arises if you then save your fla as a Flash CS4 fla. If you open up the fla in CS4 and check the font embedding options for your font now, you’ll see the following:
The window above is for the same font. Notice the total glyphs that are going to get embedded now numbers over 60,000 - this is for the same font as in the previous screenshot! The result is a compile time for your swf that can be measured in minutes rather than seconds. So if you’ve ended up with a situation where you compile is taking forever after going from CS5 to CS4, this may be something to investigate.
(I’m not sure why CS4 thinks there are so many more glyphs for this particular font than CS5, which is perhaps the weirdest thing of all.)