Yeah so I didn't think to write down the code (my bad) but based on how you said this works, I have a fair idea what happened, and probably not worth fixing, but probably worth putting a big asterisk in the usage information.

I generated a new world, by accident, thinking I was going to another one. Went "oh crap". Hit the delete world button (don't want biters evolving for no reason). Game crashed - unrecoverable error in this mod.

Hmmm. I had a theory about what might have happened, but can't get the same thing to occur even deleting the world as quickly as possible after opening it up. Without an error message/log there's not much I can do.

Yeah sorry, it was my first unrecoverable error. I just kind of clicked okay before I realised I should have captured the text.

I deleted it while it was scanning chunks into existence. After the textureless terrain had appeared. I'm guessing it was trying to add things to chunks which no longer existed or something.

Fixed in 1.0.5.