Alright I'm back, with (hopefully) good news!
I loaded your machine back up and started experimenting by deleting certain aspects that I thought would cause issues.
Turns out, for some reason, the braces in the main body of the plane were the issue, once they were deleted the simulation would start as normal, no game breaking issues.
Now unfortunately for you, this quite a structural downfall for the craft, maybe have less braces or redesign the body completely. Hopefully this helped!