KSP 1.4.3 Odd lockup

NullReferenceException
  at (wrapper managed-to-native) UnityEngine.WheelCollider:GetGroundHit (UnityEngine.WheelHit&)
  at VPWheelCollider.GetGroundHit (UnityEngine.WheelHit& hit) [0x00000] in <filename unknown>:0
  at VehiclePhysics.VehicleBase.CalculateSuspensionTravel (VehiclePhysics.WheelState wheel) [0x00000] in <filename unknown>:0
  at VehiclePhysics.VehicleBase.FixedUpdate () [0x00000] in <filename unknown>:0

(Filename:  Line: -1)

NullReferenceException
  at (wrapper managed-to-native) UnityEngine.Transform:INTERNAL_get_rotation (UnityEngine.Quaternion&)
  at UnityEngine.Transform.get_rotation () [0x00000] in <filename unknown>:0
  at UnityEngine.Transform.get_up () [0x00000] in <filename unknown>:0
  at VPWheelCollider.FixSteerAngle (Single inputSteerAngle) [0x00000] in <filename unknown>:0
  at VPWheelCollider.set_steerAngle (Single value) [0x00000] in <filename unknown>:0
  at VehiclePhysics.VehicleBase.Update () [0x00000] in <filename unknown>:0

(Filename:  Line: -1)