Root level exception in OnGUI(): System.NullReferenceException: Object reference not set to an instance of an object
  at ProsthesesCore.Verb_Jump.get_Caster () [0x00006] in <d506686719094092805947a5a02e5aaf>:0
  at (wrapper dynamic-method) RimWorld.Targeter.RimWorld.Targeter.ConfirmStillValid_Patch1(RimWorld.Targeter)
  at (wrapper dynamic-method) RimWorld.Targeter.RimWorld.Targeter.ProcessInputEvents_Patch1(RimWorld.Targeter)
  at (wrapper dynamic-method) RimWorld.MapInterface.RimWorld.MapInterface.HandleMapClicks_Patch2(RimWorld.MapInterface)
  at (wrapper dynamic-method) RimWorld.UIRoot_Play.RimWorld.UIRoot_Play.UIRootOnGUI_Patch1(RimWorld.UIRoot_Play)
  at (wrapper dynamic-method) Verse.Root.Verse.Root.OnGUI_Patch1(Verse.Root)
(Filename: C:\buildslave\unity\build\Runtime/Export/Debug/Debug.bindings.h Line: 39)

Exception in UIRootUpdate: System.NullReferenceException: Object reference not set to an instance of an object
  at ProsthesesCore.Verb_Jump.get_Caster () [0x00006] in <d506686719094092805947a5a02e5aaf>:0
  at Verse.GenUI+<TargetsAt>d__46.MoveNext () [0x00044] in <38562b1a2ab64eacb931fb5df05ca994>:0
  at Verse.GenCollection.FirstOrFallback[T] (System.Collections.Generic.IEnumerable`1[T] source, T fallback) [0x00012] in <38562b1a2ab64eacb931fb5df05ca994>:0
  at RimWorld.Targeter.CurrentTargetUnderMouse (System.Boolean mustBeHittableNowIfNotMelee) [0x0003c] in <38562b1a2ab64eacb931fb5df05ca994>:0
  at (wrapper dynamic-method) RimWorld.Targeter.RimWorld.Targeter.TargeterUpdate_Patch1(RimWorld.Targeter)
  at (wrapper dynamic-method) RimWorld.MapInterface.RimWorld.MapInterface.MapInterfaceUpdate_Patch2(RimWorld.MapInterface)
  at RimWorld.UIRoot_Play.UIRootUpdate () [0x00015] in <38562b1a2ab64eacb931fb5df05ca994>:0
(Filename: C:\buildslave\unity\build\Runtime/Export/Debug/Debug.bindings.h Line: 39)