Thank you very much st1575, that was an incredibly helpful post! I uncommented the line but the one itinerary I am trying is still giving me issues. Other itineraries seem to be working though - maybe it is just because this is only on VS or maybe the Kulula segment is the issue?
Your hunch seems correct. According to the fare rules for the VS flights (ZNRP7AMN):
Code:
TICKETS MUST BE ISSUED ON VS.
That would seem to preclude ticketing on Delta.