See, I could expect that to happen if it started using too much memory (like vanilla does when not LAA), but it's not running outta memory, I've monitored the memory while running and it doesn't even hit 1gb before it crashes, and even if it did use over 2gb, with LAA on it shouldn't crash. I tried running default MW settings on a large region, and it happens, same with medium region. The only worlds that generate, are the MW specific worlds. If I can't generate a large region with default MW settings... That sounds like an issue in MW, especially since I can do it just fine with vanilla DF.
[EDIT] I don't mean to sound ungrateful or rude, I just have heard nothing but good things about MW, and I really want to play it, I just want to be able to play it in a similar type of world that I typically play DF in.