I tried the above and the game still freezes at a certain point, when a civilian is jumping through a window, only seems to happen if one of my troops sees it happening though, so it's still kind of playable. The fact that it's consistently happening makes me think there's either a problem with the map or how the civilian AI is coded, or the interactions between them, don't know if there's a way to fix it by replacing some of the maps.
Is there any way to revert to the 0.25HF version anymore with a Steam version of Xenonauts?