Looks like I'm not the only one here with the same issue. It would appear you have a save bug since the most recent patch.
I have had it happen on mission 10 and 11.
I have had five hard crashes to win 10 (win error reporter activates) with no bug file via WfTO folders.
This is particularly annoying, as I have defeated Deimos, and have now beaten Kiera five times, eacfh time trying to save freezes the game, and after a min crashes to desktop.
Gigabyte Z270X Mboard.
16 gig ram
SSD (samsung evo)
Customer support service by UserEcho