samatar: I have this issue too. I tried running the Graphic Mode Setup application but it just says "Error: Game not installed". The game works so it is obviously installed... I removed and reinstalled it, ran graphic mode setup again but it still says the game is not installed. I also tried changing "output" in dosboxmc.conf to opengl but this made no difference, the game still won't generate spells (or generates them very sporadically) when I am on a level with large numbers of objects. Any help would be appreciated, I already played all the way through this game using cheat codes to remove some of the extra civilians in the game but obviously I would prefer not to have to overcome the issue in this manner...
have you tried running it from the start menu? somehow changes in the display settings just work when you start the setup from your start-menu not from the the folder itself
EDIT:
but this didnt help for me. still cant cast any spell on this level. when i restart it its the same. first i can cast, later i cant... no matter if i choose opengl, surface, direct3D whatever. always the same...
im pretty sure it has something to do with the population (when its growing to much) it grows huge at this level but how can i avert this?? I hope there is a solution cos its unplayable like this :-(