game unable to lunch properly mission following the death of helga von bulow

Hello dear devs, in campaign mode, after killing helga, the cinematics are played, but after briefing i think there's un bug, blasko is the the briefing room, but i'm unable to do anything with him to interact with other characters or with item except the clock. I only can jump by the window but fall in the backyard, and there's no exit. Can you tell me more about this ? Thanks