It seems that several months of contract configurator updates left GAP in the dust; i'd recommend avoiding all contracts that spawn vessels in; i've had my game nullref (and almost lost my save) because of a glitched vessel spawn, and that's on the October version of CC.
from: https://forum.kerbalspaceprogram.com/index.php?/topic/129208-contract-pack-giving-aircraft-a-purpose-gap-129-air-flights-tours-coast-guard-sts-oct-28-2016/&do=findComment&comment=2960106
It seems that several months of contract configurator updates left GAP in the dust; i'd recommend avoiding all contracts that spawn vessels in; i've had my game nullref (and almost lost my save) because of a glitched vessel spawn, and that's on the October version of CC.