Hey what I could see so far from this track this could get really great
I would also suggest using the latest blender (2.79b) but don't use 2.8 yet when it is released because it is currently incompatible.
With Blender 2.79b I could export the track without an error (only a warning about not activated checklines, I guess at this point they are missing completely).
But when I wanted to start it STK crahes with the error message: DriveGraph: Fix graph, check for directions of all shortcuts.
First of all I would suggest giving better names to objects that have an important function, for example a driveline is called Plane.0003 or the cannon flight path is called BezierCurve.
But it looks like you have some issues:
the cannonstart.001 has the wrong Flight end line and path set
instead of cannend it should be cannend.001 and instead of BezierCurve it should be BezierCurve.001
Or did you want to not use the second cannon (that goes upwards) for now, because to upper driveline is not set to driveline and leads nowhere and the maindriveline is close.
For testing I set the type of cannon start and cannon end to none.
But the real issue why it fails is that there are additional drivelines in the track part that's really far away from the rest, for testing I deleted this.
The problem here I guess is that the additional driveline is not connected to the maindriveline.
I am speaking of the part here on the right:
So after deleting the additional drivelines, when I started I got an crash saying SPMeshLoader::Armature: Non-parent bone missing inarmature
So there seems to be a bone issue.
I deleted every object that has bones and tried again and it worked.
So you need to either connect the additional drivelines to the main driveline or if you want to test you have to set these additional drivelines to object type none.
And you have to check all objects that have a armature/bones. You can find out which object causes the problems by doing multiple exports every time with an different armature object deleted.
I am looking forward to that track