May 09, 2014, 04:10:46 am
Have had a look at your scene.
I found clip 19 sets the message because there is an animated Sun (Sun Position is keyframed).
Clip 23 (heavy/slow play back) does not have the message. There is a Sun Study Effect, but no sliders are set with keyframes, so things like Sun Position that affect the lighting do not require Lumion to recalculate the lighting for the scene.