NullReferenceException when enable and disable curves with followups

[phaix]

Hey, i have the problem that when i enable and disable parts of my level it always throws Null Ref Errors. This happens when i disable segments behind the player and enable other segments in fron of the player. 

Code:

NullReferenceException: Object reference not set to an instance of an object
FluffyUnderware.Curvy.CurvySplineSegment.CanFollowUpHeadToEnd (FluffyUnderware.Curvy.CurvySplineSegment followUp) (at Assets/Plugins/ToolBuddy/Assets/Curvy/Scripts/Splines/CurvySplineSegment.cs:2079)
FluffyUnderware.Curvy.ConnectionHeadingEnumMethods.ResolveAuto (FluffyUnderware.Curvy.ConnectionHeadingEnum heading, FluffyUnderware.Curvy.CurvySplineSegment followUp) (at Assets/Plugins/ToolBuddy/Assets/Curvy/Scripts/Splines/Connections/ConnectionHeadingEnumMethods.cs:25)
FluffyUnderware.Curvy.CurvySpline.GetFollowUpHeadingControlPoint (FluffyUnderware.Curvy.CurvySplineSegment followUp, FluffyUnderware.Curvy.ConnectionHeadingEnum headingDirection) (at Assets/Plugins/ToolBuddy/Assets/Curvy/Scripts/Splines/CurvySpline.cs:879)
FluffyUnderware.Curvy.CurvySplineSegment+ThreadSafeData.Set (System.Boolean useFollowUp, FluffyUnderware.Curvy.CurvySplineSegment curvySplineSegment, FluffyUnderware.Curvy.CurvySplineSegment& nextCP) (at Assets/Plugins/ToolBuddy/Assets/Curvy/Scripts/Splines/CurvySplineSegment.ThreadSafeData.cs:75)
FluffyUnderware.Curvy.CurvySplineSegment.PrepareThreadCompatibleDataINTERNAL (System.Boolean useFollowUp) (at Assets/Plugins/ToolBuddy/Assets/Curvy/Scripts/Splines/CurvySplineSegment_private.cs:682)
FluffyUnderware.Curvy.CurvySpline.PrepareThreadCompatibleData () (at Assets/Plugins/ToolBuddy/Assets/Curvy/Scripts/Splines/CurvySpline_private.cs:1024)
FluffyUnderware.Curvy.CurvySpline+DirtinessManager.ProcessDirtyControlPoints () (at Assets/Plugins/ToolBuddy/Assets/Curvy/Scripts/Splines/CurvySpline.DirtinessManager.cs:293)
UnityEngine.Debug:LogException(Exception, Object)
FluffyUnderware.DevTools.DTLog:LogException(Exception, Object) (at /Users/daniel/Repositories/VR_Sugarhill/Assets/Plugins/ToolBuddy/Dependencies/DevTools/Classes/DTUtility.cs:936)
FluffyUnderware.Curvy.DirtinessManager:ProcessDirtyControlPoints() (at Assets/Plugins/ToolBuddy/Assets/Curvy/Scripts/Splines/CurvySpline.DirtinessManager.cs:306)
FluffyUnderware.Curvy.CurvySpline:Initialize() (at Assets/Plugins/ToolBuddy/Assets/Curvy/Scripts/Splines/CurvySpline_private.cs:637)
FluffyUnderware.Curvy.CurvySpline:OnEnable() (at Assets/Plugins/ToolBuddy/Assets/Curvy/Scripts/Splines/CurvySpline_private.cs:431)
UnityEngine.GameObject:SetActive(Boolean)
LevelController:SetSectionVisibility(LevelSection, Boolean) (at Assets/05_Scripts/LevelController.cs:287)
LevelController:Update() (at Assets/05_Scripts/LevelController.cs:258)