Quote Originally Posted by alpaca
I think that the files are still read from the pack.
That's what I thought too, hence renaming the file in the pack so that it couldn't - this does work, I accidently tried to run the battle editor without changing it back and the game had a whingefess about not being able to find any regions.

Anyway, a quick sumary to show where crashes were happening (the only real way to tell them apart) -

File in Pack = Campaign starts fine
File in pack + .txt file = .bin created, game crashes when clicking on start campaign
File in Pack + .bin file = Campaign starts fine, changes have no effect though
File in pack renamed = Crash when clicking on "Grand Campaign"
File in pack renamed + .txt file = .bin created, game crashes when clicking start campaign
File in pack renamed + .bin file = Game crashes when clicking start campaign

Judging by the crash behaviour then, I would conclude that the external files will overide the pack when the .txt file is present, otherwise the pack takes precedence. However, the .bin that is generated is broken, so it's a moot point for now anyway.