Our U.S. Steam version has not been updated. That is the only version we support.
EU Steam has the same version as US. The trainer works fine on Steam as I just played for a while about 2 hours ago.
You have to do exactly as PWizard says. Activate the trainer (F1) at the main menu (after the "press any key" screen), not when you go to select the heist. After that you can activate the other options while you're playing.