This is in regards to "The Swiss Emerge" hardcoded event around the late 1300s to early 1400s. If you're making a new map or campaign, without including the Swiss, the game crashes with a "No portrait found" error. My first inclination was to make sure Switzerland was included as a region and that the Swiss were included as a major or minor faction. I tested this and it worked fine all the way through the endgame; but if you want the Swiss (or whatever new faction you mod them into) to emerge, there is an easier way. You would still need to have Switzerland as a region and include them in the following
SetStartLeader::
Normally, you would need PlaceLeader:: also for all factions, but you won't need it for the Swiss if you want them to emerge. Of course you would need to change the other basic stuff to have them in the game, but that is the main difference from the Swiss emerging and "regular" factions. Btw, this is how it's done in the default Early.txt