System.NullReferenceException: Object reference not set to an instance of an object
at RimWorld.StockGenerator_Animals/<HandlesThingDef>c__AnonStorey2.<>m__0 (string) <0x00029>
at System.Collections.Generic.List`1<string>.GetIndex (int,int,System.Predicate`1<string>) <0x00050>
at System.Collections.Generic.List`1<string>.FindIndex (System.Predicate`1<string>) <0x00066>
at Verse.GenCollection.Any<string> (System.Collections.Generic.List`1<string>,System.Predicate`1<string>) <0x0005f>
at RimWorld.StockGenerator_Animals.HandlesThingDef (Verse.ThingDef) <0x000ec>
at RimWorld.TraderKindDef.WillTrade (Verse.ThingDef) <0x00054>
at RimWorld.Dialog_SellableItems.CalculateSellableItems (RimWorld.TraderKindDef) <0x0017c>
at RimWorld.Dialog_SellableItems..ctor (RimWorld.TraderKindDef) <0x00144>
at RimWorld.Planet.SettlementBase/<GetGizmos>c__Iterator0.<>m__0 () <0x0007b>
at Verse.Command_Action.ProcessInput (UnityEngine.Event) <0x00038>
at Verse.GizmoGridDrawer.DrawGizmoGrid (System.Collections.Generic.IEnumerable`1<Verse.Gizmo>,single,Verse.Gizmo&) <0x00c75>
at (wrapper dynamic-method) RimWorld.InspectGizmoGrid.DrawInspectGizmoGridFor_Patch0 (System.Collections.Generic.IEnumerable`1<object>,Verse.Gizmo&) <0x007d6>

Verse.Log:Error(String, Boolean)
Verse.Log:ErrorOnce(String, Int32, Boolean)
RimWorld.InspectGizmoGrid:DrawInspectGizmoGridFor_Patch0(IEnumerable`1, Gizmo&)
RimWorld.Planet.WorldInspectPane:DrawInspectGizmos()
RimWorld.InspectPaneUtility:ExtraOnGUI(IInspectPane)
RimWorld.Planet.WorldInspectPane:ExtraOnGUI()
Verse.WindowStack:WindowStackOnGUI()
RimWorld.UIRoot_Play:UIRootOnGUI()
Verse.Root:OnGUI()