Unspecified error on loading campaign save

[Lightfall]

Just recently I've started getting a CTD every time I try to load a campaign game. This happens whichever faction I'm playing, and whether I hit 'continue campaign' or load a save from the list. It's an 'unspecified error', and there's no further info in the log, so I've no idea what to do. I can start campaigns fine, but unless I do a whole campaign in one go, I'm screwed.

Anybody encountered this/have any idea what might be causing it?

[StealthFox]

Are you playing with any submods or have you edited any gamefiles? This can cause this if you're editing files between saving and loading.

[Lightfall]

I have been modding, but now it's happening if I start a new campaign then save and quit and immediately try to load it, so it's not modding between saving and loading that's the problem. Also, I've been modding the game for ages, and I've not changed any files recently that I haven't before, which is why I'm so confused as to why it's suddenly a problem...

[Lightfall]

By copying in clean backup files I think I've narrowed down the problem to the map files. Are there any experts on mapping who might be able to tell me how these files could be causing no problems for the game when starting a campaign, but critical problems during loading?

[Lightfall]

Unless of course the problem is with the loading screen itself... I have absolutely no idea how any of the editing I've done could have affected this - I've gone nowhere near any UI-related files - but could any other modding somehow cause that? Seriously clutching at straws now...