Screenshots of my game turn out black

I was trying to take screenshots of my game at various points, but they all turned out entirely black. I tried with the Windows print screen function and with Lightscreen (my preferred method as it auto saves each time I capture). Neither of them were able to capture the screen.

Does anybody else experience this or know what could be causing the problem? I’m doing this with the game in fullscreen, could it be a problem with the fullscreen rendering?

Have tried but yeah, can’t take screenshots in fullscreen. Can’t even capture video in fullscreen.

I just tried capturing video with Open Broadcaster Software and it worked using monitor capture. Haven’t tried window or game capture though.