Fear of Unpacker

I have done some modding in M2 but in Kingdoms I got into trouble when unpacking. I need to know how unpacking actually works and why when I unpacked in Kingdoms I got errors and crashes when trying to run a battle in an existing game, after making what I thought was a simple change in the ancillary file. Is there a new unpacker app that works with Kingdoms, or, because kingdoms has a sub folder for each game set ( Crusade, Teuton, America...etc.) I would like to just unpack maybe one set of files at a time so I can try to keep track of what I am doing and where the problems arise. Just running the unpacker app and modding the files then saving them does not seem to work. The sys log shows massive errors too confusing for me to see what is going on.

I know there are several data files. Although I dont have the stuff in front of me right now ( I keep my gaming PC off line for security reasons ) it seems that each game set has their own. So, is there somewhere I can find an explanation of how the file structure is set up? I think if I could understand the structure better, I could understand what the thing is doing when I unpack.

Thanks in advance.