I'm on the last mission of XCOM: Enemy Unknown. I just defeated two Sectopods, and now I'm not sure how to go any farther. The area up ahead is dark, and the game won't let me move any further. Here is a screenshot of where I'm at:
Do you know what I can do in order to proceed? I've tried reloading my last save, and also reloading an earlier save (from just before I attacked the Sectopods). I haven't tried restarting the mission yet, and I'd like to avoid that if possible, but that is something I could try I suppose.
If it matters, I'm playing on OS X via Steam, and don't have Enemy Within installed.