i am having the same issue, didn't know it was an issue till i saw this now, i am also using 1.3, its actually says parsing and then its stuck, fully frozen, its really big scene, up to 400 mb and i am using laubwerks for all my trees and alot of high poly models so am not sure whats going on, when this happens i have to restart 3ds max so its just a matter of saving before i start to render incase i get stuck