wip, model crashing the program

[USS Sea Tiger]

U-31 class boat,

all parts exported,

made sure the poly count matched on each part exported to within 2 percent.

the boat will load run and play 1 out of about 7 loads in single mission mode.

the other times it crashs at about 1/10 load on the bar or at 65 percent load on the bar.

any clue what might be causing this issue??

thanks


Mike D