I did some experimenting in Free Flight, and have some updated information:
I went into Free Flight and did a whole flight in flatscreen mode, without ever turning on my headset, hitting Ctrl+Tab, or anything like that. Startup, takeoff, cruise, landing, and shutdown. I took several photos during this flight without incident, and they showed up in my Screenshots directory. Each time, I saw the little thumbnail appear in the lower right.
After landing and shutting down, I took one more picture, and then put on my headset, went into Virtual Desktop, and then once I was looking at the sim, I pressed Ctrl+Tab to go into VR mode. Once in VR mode, I walked around a bit outside my plane, and attempted to take some more pictures. None of these worked. In fact, the first time I attempted to take a picture, the reticle disappeared entirely, though I could continue to click the button to “take more pictures” and I would hear the shutter sound, but at no point after entering VR was I able to actually take a photo, see the icon, and have it save to the directory.
I then pressed Ctrl+Tab again to exit VR. I quit out of Virtual Desktop on my headset, and shut it down. I was once again watching the sim on my actual monitor, no VR involved at all. I again entered photo mode and attempted to take a picture. Still nothing–shutter sound, but no thumbnail, and no photo stored to the directory. At least the reticle didn’t disappear this time.
One last test–I exited back to the free flight menu, picked a different aircraft, and started another flight from the same aircraft (in flatscreen mode–my headset was still turned off and on the shelf). Upon spawning in, rather than doing the usual walkaround, I immediately entered photo mode and attempted to take a picture of my new aircraft–still no photo taken.
So I’m pretty sure now that this is VR related, and it’s not as simple as “you can’t take pictures in VR mode.” That would at least make sense, as while I could (and often did) take pictures in VR mode before, judging what was “in the shot” and not was difficult since the photo seemed to be my whole FOV not just what was in the reticle. No, somehow entering VR breaks something, such that exiting VR (or even exiting back to the menu and starting a new flight) doesn’t turn it back on again. This breaks World Photographer mode unless you’re willing to go flatscreen the whole time (you can’t even just turn off VR long enough to frame your shot and take it, and then go back into VR once you’ve taken the picture) but isn’t unique to that mode, and affects photography in any mode.