Re: THE NATIVE UNITS FROM warpath campaign TO GRAND campaign
I generally couldn't successfully make or edit mods using PFM 3.X (3.1.2, etc). I have not tried PFM 4.1.2.
Pike square is an ability which can be added to colonial pikemen. You might need to edit a separate abilities table to add this ability. (I might have added this ability to Colonial Pikemen in my Minor & Emergent Factions Unit Pack, so you could try looking at that mod file, to see how to do this.)
In my experience, sometimes a mod file causes CTD during the loading of the game when I mis-spell something in a database table - and sometimes (as in your experience) this happens when I cannot find any typing error. I do not know of any solution for this, apart from to go back to an earlier version of the mod (or to re-make the mod from scratch). If the game keeps crashing even when you have removed the mod file which causes the problem, you could try the ideas listed here under the heading 'How to recover when the game becomes broken'. I found that when I tested a series of 'work in progress' mod files, eventually I needed to delete and re-install the game.