nonpareil

I've run into a bug - some of the companions have completely vanished from the Unreliable. I can't interact with where they should be, and although the ship interactions between companions are still happening, the vanished companion's voice isn't there. Also, when I'm out with them, they appear on the ground as if dead, and I can't interact with them. The quest marker leads me to an empty space. This is making it impossible to finish their quests... has anyone else had this problem, and if so, how did you fix it? I'm playing on Windows 10 with the Windows Store player. I've uploaded a screenshot here. And another one where the interaction is going on even though one character is missing. As you can see, it makes things difficult in more than one way.