hi!
regarding to the pm i wrote, here's the post with the .tgd attached.
short description of the crash: happens after about 75% of the render finished, happens with and without population, so no problem there. could be a problem with clouds hitting terrain which is directly below the clouds (though not likely, rendered images with clouds interacting with terrain without any problems), or could be a problem with water, or something i just don't see.
thanks in advance for looking into it, no need to hurry, it's only my image-challenge-entry =)
cheers...