I'm playing 5.9.21 with BI so this may already be fixed in newer versions. I unlocked all factions as playable in the Caesar campaign and have customized some models in the DMB but have made no other changes in the code.
When I play as Bactra in the Caesar Campaign and try to capture Campus Yuezhe i get a CTD. It also crashes if i try to send in a spy and view the settlement. It's not a missing texture or model CTD as I am very familiar with those, and haven't changed any units involved in this specific action.
Also thanks for still keeping XGM alive, years later and I'm still drawn to XGM