I am a mac user whose running the game without terrain due to my graphics card. When I run a mod, it only takes a few seconds for a CTD. Now, the odd thing is that the mod seems to run better when the settings are set to draw_terrian=yes, by which I mean it does not crash immediately but waits till it has to load graphics. It seems that the very thing that makes Crusader Kings work on my computer stops me from running mods.