Good night!
I have encountered similar situation earlier (don't remember it happened in Xeno or PirateZ mods),
but one of nightly builds was always crashed during an alien faction turn in battlescape.
I have bypassed this situation by demoralizing all aliens (by setting
morale: 0for all units with
faction: 1 (aliens) value in the battlescape saved game file,
so all aliens panic/berserk next turn (even HWPs: cyberdisks, sectopods, etc.),
and no any crashes.
I made this for you, too. Try it and report if it help or not.
If no, then i'm try some similar method.