Node is null - you must called EnsureGraphicsInitialized() on the drawn dynamic thing Zimmerman before drawing it. UnityEngine.StackTraceUtility:ExtractStackTrace () (wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.Log.Error_Patch5 (string) Verse.Log:ErrorOnce (string,int) Verse.PawnRenderTree:TraverseTree (System.Action`1<Verse.PawnRenderNode>) System.Reflection.MonoMethod:Invoke (object,System.Reflection.BindingFlags,System.Reflection.Binder,object[],System.Globalization.CultureInfo) System.Reflection.MethodBase:Invoke (object,object[]) NiceHealthTab.OverlayGeneCache:CallTraverseTree (Verse.PawnRenderTree,System.Action`1<Verse.PawnRenderNode>) NiceHealthTab.OverlayGeneCache:SolveCache (Verse.Pawn) NiceHealthTab.DollDrawer:DrawAllDolls (UnityEngine.Rect,Verse.Pawn,bool) NiceHealthTab.Patches/DrawHediffListing_Patch:Prefix (UnityEngine.Rect,Verse.Pawn,bool,bool) (wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:RimWorld.HealthCardUtility.DrawHediffListing_Patch1 (UnityEngine.Rect,Verse.Pawn,bool,single,bool) NiceHealthTab.Patches/HealthCardUtility_DrawPawnHealthCard_Patch:Prefix (UnityEngine.Rect,Verse.Pawn,bool,bool,Verse.Thing) (wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:RimWorld.HealthCardUtility.DrawPawnHealthCard_Patch4 (UnityEngine.Rect,Verse.Pawn,bool,bool,Verse.Thing) (wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:RimWorld.ITab_Pawn_Health.FillTab_Patch1 (RimWorld.ITab_Pawn_Health) Verse.InspectTabBase/<>c__DisplayClass19_0:<DoTabGUI>b__0 () Verse.ImmediateWindow:DoWindowContents (UnityEngine.Rect) (wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.Window.InnerWindowOnGUI_Patch0 (Verse.Window,int) UnityEngine.GUI:CallWindowDelegate (UnityEngine.GUI/WindowFunction,int,int,UnityEngine.GUISkin,int,single,single,UnityEngine.GUIStyle)