Indeedly, what Sura suggested about the particles is most likely the case with these frequent crashes you're experiencing.
So, you probably just have some unruly extra particle files left in there that's throwing off the game's rendering system. In the future, as soon as you export a map, go ahead and check your particle folder before you even restart FH again. It's a good habit to have if you're a frequent map maker, and it'll definitely save you some confusion, as well.
Good luck, and let us know if any problems persist. c:
