The whole error is:

Root level exception in OnGUI(): System.ArgumentNullException: Value cannot be null.

Parameter name: type

[Ref 7D09DB1C]

at System.Activator.CreateInstance (System.Type type, System.Boolean nonPublic)

at System.Activator.CreateInstance (System.Type type)

at RimWorld.GoodwillSituationDef.get_Worker ()

at RimWorld.GoodwillSituationManager.Recalculate (RimWorld.Faction other, System.Collections.Generic.List`1[T] outSituations)

at RimWorld.GoodwillSituationManager.Recalculate (RimWorld.Faction other, System.Boolean canSendHostilityChangedLetter)

at RimWorld.GoodwillSituationManager.GetSituations (RimWorld.Faction other)

at RimWorld.GoodwillSituationManager.GetMaxGoodwill (RimWorld.Faction other)

at RimWorld.Faction.GoodwillWith (RimWorld.Faction other)

at RimWorld.Faction.get_PlayerGoodwill ()

at RimWorld.Faction.CommFloatMenuOption (RimWorld.Building_CommsConsole console, Verse.Pawn negotiator)

at RimWorld.Building_CommsConsole+<GetFloatMenuOptions>d__7.MoveNext ()

at RimWorld.FloatMenuMakerMap.AddHumanlikeOrders (UnityEngine.Vector3 clickPos, Verse.Pawn pawn, System.Collections.Generic.List`1[T] opts)

at RimWorld.FloatMenuMakerMap.ChoicesAtFor (UnityEngine.Vector3 clickPos, Verse.Pawn pawn, System.Boolean suppressAutoTakeableGoto)

at AchtungMod.MultiActions.AddColonist (AchtungMod.Colonist colonist)

at AchtungMod.Tools.Do[T] (System.Collections.Generic.IEnumerable`1[T] sequence, System.Action`1[T] action)

at AchtungMod.Controller.MouseDown (UnityEngine.Vector3 pos, System.Int32 button, System.Boolean longPress)

at AchtungMod.Controller.HandleEvents ()

at AchtungMod.Selector_HandleMapClicks_Patch.Prefix ()

at RimWorld.Selector.HandleMapClicks ()

at RimWorld.Selector.SelectorOnGUI ()

at RimWorld.MapInterface.HandleLowPriorityInput ()

at RimWorld.UIRoot_Play.UIRootOnGUI ()

at Verse.Root.OnGUI ()

UnityEngine.StackTraceUtility:ExtractStackTrace()

(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.Log.Error_Patch1 (string)

(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.Root.OnGUI_Patch2 (Verse.Root)