As I said, I have a lot of custom reactions and stuff in my raw files (dwarves can make goblin/elf/human brain roasts, kitties and domestic animals breed really slowly, hair becomes silk, cartilage becomes shell, library mod, dwarves are adult at the healthy age of 7, it's possible that microcline is modded to be a flux material, crematorium mod, etc etc etc. (no, I don't have any respect for the vanilla settings.))
Would I need to zip all of it for the save to work? And anyway, where would I put it?
It may be a result of a shoddily done installation of 31.13 on top of a copy of my 31.12 directory. I didn't want to be bothered to have to put all my raw and art and init files back into the new version, so I just unzipped anything new into the existing directory.
Also, I am settling on a very pretty peak with the magma pipe in the middle and some 80ish extra z-levels of extra sky on top of everything now. I selected this one because there's aquifer in the immediate proximity of the peak and sand. Also because the environment is such a lovely lifeless tundra.
The FPS stutters every couple of seconds, but that aside, I didn't get any migrats in the first year. I thought that this was quite awesome until the first one arrived next spring. Population_cap should be set to 1.