OK, long and the short on this one.

I've got thirty-ish hours into the campaign, and I've completed one Stronghold mission, against the Necrons.
However, every time I attempt the Chaos Stronghold, it crashes to desktop *exactly* twenty minutes into the mission.
I've attempted running the game in Safe Mode, I've attempted lowering the graphical settings, and I've wasted the last four hours trying to find patches or hotfixes for a relatively rare issue.

Any help would be greatly appreciated!

I still have to play Dark Crusade, but for what I read, it's a common bug, you have to make regular saves to progress. Hope it helps.