Cannot set alpha on dynamic text in Flash / ActionScript 2

Problem

I’m doing some freelance Flash development, and it’s been a while. I have just created a dynamic text field that I wanted to fill via actionscript, then fade in via an alpha tween. This wasn’t working, even if I set _alpha = 0 on the movieclip containing the text field.

Solution

You can only set _alpha on a Dynamic Text field if the font has been embeded (with the embed button).

Works now! wohoo! Simple stuff that I’ve known in the past, but forgot.