Follow these steps precisely in order to get the scene with the seated pose:
1/ Load G8F and select it.
2/ Open timeline tab and check that the cursor is positioned on frame 0.
3/ Load the complete preload clothing set (wearables)
4/ Go to the subfolder props and load the complete preload (set). You will notice that keyframes have been added to the timeline.
5/ Select G8F, move the cursor to frame 15, and apply the seat pose provided. For the purpose of the pose the armchair is animated, do not modify the position of the armchair in frame 15.
6/ Reposition the timeline cursor on frame 0. Go to simulation settings and set the parameters as follows: "Start Bones From Memorized Pose" OFF / "Frames To Simulate" choose Animated Use Timeline Play Range.
7/ Start the simulation.