CTD English attack Rennes

[King John II]

I am the English in the Early Campaign. I send an army to invade Brittany and besiege Rennes. I opt to wait and starve them out because it is easier if they attack me rather than the other way round. I wait 4 turns. It is turn 11 and I hit the 'end turn' button. The game cycles through the factions until it gets to the rebels and my army is attacked by the garrison attempting to break the siege. The army composition screen pops up and I chose to fight the battle on the battle map. I get a loading screen with some mounted troops in plate armour in a town (it 's always the same picture). The status bar gets about 3/4 of the way along and then the game crashes to desktop. Why?

[bɑne]

Log seems a bit thin, please specify your version, campaign options in ss setup and upload a save if possible.

[King John II]

Version 6.4

Early Era
Savage AI
Byg's Grim Reality IV
Longer Assimilation
Permanent Arrows

Nothing Else.

[King John II]

Update:

Restarted the game and began besieging Rennes earlier this time. Turn 8 comes, the garrison attacks and it still crashes to desktop during the loading screen.

The game has a thing for the Bretons, I guess.