So my SVN game was crashing 1106BC consistently on turn end, when a lackadaisical auto piloted bandit with march promotion no less was parked healing next to a town with a crap ton of siege units (as all the AI overdo - 175 siege rams alone, never mind the onagers and whatnot - it was obviously off the screen). Thankfully, since the idiot bandit

was healing in harms way, it had it's full move available and was I was able to move it the hell away from the town and not have to delete the moron, bam no more crash moving to 1099BC.
I have fight or flight on, but none of the other mods like size matters etc , not sure all that helps but something about a metric ton of AI ranged bombardment can do strange things.
Turns out this is a repeatable bug with any of the AI controlled AI Siege 'Mountains'. The game crashes on the inter-turn as I'm dealing with their defences, as the siege try and spam me. I had to turn off Siege ranged bombardment to let the turns process without crash to desktop, this after deleting my outlaws and sharpshooters

..... bah, snipers soon enough to cover it all.
Edit:
Bandit related again, but a bug that does not CTD at least

. It appears, to the best of my bandit/strike_team focus, that Vanilla's code has issues with class specific promotion availability when a upgraded Trooper changes basic class (e.g. melee based assassins upgraded to gunpowder sharpshooters). What this boils down to is say the gunpower based Sniper skill, a highwayman built from the factory can access the promotion after combat 4, but a bandit rider with combat 4+ upgraded into a highwayman will never see sniper offered as a promotion. I can only assume the game still somehow considers the upgraded bandit rider is still melee when it comes to promotions; something is not getting updated with the unit's ID.
Cheers!
-Liq