I have issue relating to the completion of rank 3 "introduction to story mode" inside "story: Ancienne earth, Russia" in the "activity" panel. I can't get it to complete rank 3, I have 9555 frags and a completion level of 86 (I don't know what it means). And I do not know what kind of action triggers the completion of this feature. I did all of earth with all 3 classes of character but no hope. Please help me !