You can add popup messages with: Venus, Waterhouse, Stig, Computer and Tami.

- When I want to select the message the "play" button don't play the clip I've selected but the one before, no big deal as I can just check the wav files with another player if in doubt.

- But usually the messages don't play at all (when playing the mission), the only thing I've ever managed to get working is to make Stig complain when building a chicken farm, all other attempts have resulted in the person popping up in the message window but the message is not played. They just sit there for a short time and then disappear. I've tried messages related to other buildings and to the timer but no luck at all.

This is often caused by another sound effect playing at the same time, so one cancels the other out. Try moving the message up or down by x hours.