You cannot break up TerrainTypes.xml without breaking its functionality. It has to be in one file.

PS. You should post these mod questions in the mod section.

If a map has terrain that is properly defined, and then you load the map without the terrain.xml, the map will crash the game. I can only assume that the basic terrains therefore have some sort of redundancy built into the main elemental.exe. It is, in my mind, propbable that these redundant terraintypes were what was loaded, since you broke the structure of the original terraintypes.xml.

As far as I know, these redundancy checks only appear in terraintypes and environmenttypes.

If you do not break the file, your changes will function.

In my opinion, a mod that does not function does not qualify as a "bug". The problem is the mod, not the original files. Maybe I am wrong, but that's how I see it.

So I recopies the terraintype.xml in it's original position and removed my files.

I have modifiied 3 parameters in the terraintype.xml (exacly the same as above)

and nothing happens.

It really looks like an obsolete file, or like you said, there is a backup file somewhere.

Hmm Weird. I have 2 computers with the same game, I'll try doing it on my second computer.