Game not running in Steam after simple EDU & EDB mod and [io] file_first change to pref file

[Drgoodspeak]

MTW2: Kingdoms, Steam, Windows 10

Hi, all I'm trying to do is add the accursed Sergeant Spearmen and Armoured Sergeants for England in the main campaign. That's it.

I unpacked the files, added the ownership against the units in the EDU and then made sure England was added against the units in the correct building types in the EDB. I get all that.

I've read the stuff about the change needed to the medieval2.preference.cfg file, to add in [io] file_first = true, but here's the problem:

1. Without the file_first bit, the units don't show in the campaign with the correct buildings built.
2. With the file_first bit in the .cfg file, I get the first splash screen on loading and then it just closes. I don't get as far as the "soundblaster" splash screen.

I've spent close on 3 hours trawling forums trying to get an answer to this and I am defeated. I understand there are some complexities using mods with Steam (For the record, I have the original game CD, but can't find my Kingdoms expansion, so bought it on Steam), and I'm sure I might be missing something beyond my limited knowledge.

I understand how the mods folder works, but as my desired change is so minor, I thought I'd get away with just the two text file edits.

Can someone help please?

Cheers.

[Drgoodspeak]

Anybody? What I don't really understand is that having modified core files, why should I point the launch towards them using the "file_first" bit? Would it not use the core files anyway? Is it because the launch is otherwise using packed files? Once you unpack, are the unpacked files additional to the original packed files? Without the "file_first" bit, does the launcher still use the packed files, which would explain why the changes I have made are not showing I guess.

I'm not asking anyone to troubleshoot a Steam launch issue, I guess I need more of an understanding of how this all works.

Surely someone out there using Steam must have done what I've attempted?

Is the answer to establish a basic mod, with only the change the one I'm after?

[Gigantus]

I am assuming you are modding the man campaign? Then install my modding set up and do your modding in there - it will save you loads of head aches.
Then check this tutorial.