After further testing, it looks to be an issue with generating the Head texture. When switching the head using CharacterEditor to a Furskin (Yttakin) variant, the error stops. When going back to a normal head variant (Like Female_AverageNormal), the bug occurs again.

I've noticed this issue too, I'm not sure what's causing it but I hope to address it soon.

i ran into this when a creepy joiner anthro cat entered the map. he was invisible. i checked the error logs and it seemed to point to something with the head gene. i used dev mode to remove the gene from that pawn and sure enough the error stopped and he was visible again.

Originally posted by log:

Root level exception in Update(): System.NullReferenceException: Object reference not set to an instance of an object
[Ref FCA45548]
at Anthrosonae.FurGene.GetGraphicOverriden (Verse.Graphic original, Verse.PawnRenderNode source, Verse.Pawn pawn) [0x00065] in <62cf9e8f828a4fcc8921463d0810431d>:0
at Anthrosonae.PawnRenderNode_Head_GraphicFor_Patch.Postfix (Verse.PawnRenderNode_Head __instance, Verse.Pawn pawn, Verse.Graphic& __result) [0x00022] in <62cf9e8f828a4fcc8921463d0810431d>:0
at Verse.PawnRenderNode_Head.GraphicFor (Verse.Pawn pawn) [0x0009d] in <d2f9716cc2ac4cda9c2a174cc147bf37>:0
- POSTFIX OskarPotocki.VEF: Void VEF.Genes.VanillaExpandedFramework_PawnRenderNode_Head_GraphicFor_Patch:Postfix(PawnRenderNode_Head __instance, Pawn pawn, Graphic& __result)
- POSTFIX RedMattis.BetterPrerequisites: Void BigAndSmall.PawnRenderNode_Head_Patches:PawnRenderNode_Head_GraphicFor_Patch(PawnRenderNode_Head __instance, Pawn pawn, Graphic& __result)
- POSTFIX AnthrosonaeMod: Void Anthrosonae.PawnRenderNode_Head_GraphicFor_Patch:Postfix(PawnRenderNode_Head __instance, Pawn pawn, Graphic& __result)
at Verse.PawnRenderNode+<GraphicsFor>d__69.MoveNext () [0x00031] in <d2f9716cc2ac4cda9c2a174cc147bf37>:0
at Verse.PawnRenderNode.EnsureInitialized (Verse.PawnRenderFlags defaultRenderFlagsNow) [0x00071] in <d2f9716cc2ac4cda9c2a174cc147bf37>:0
at Verse.PawnRenderNode.EnsureInitialized (Verse.PawnRenderFlags defaultRenderFlagsNow) [0x001be] in <d2f9716cc2ac4cda9c2a174cc147bf37>:0
at Verse.PawnRenderTree.EnsureInitialized (Verse.PawnRenderFlags defaultRenderFlagsNow) [0x00010] in <d2f9716cc2ac4cda9c2a174cc147bf37>:0
at Verse.PawnRenderer.EnsureGraphicsInitialized () [0x0000c] in <d2f9716cc2ac4cda9c2a174cc147bf37>:0
at Verse.PawnRenderer.DynamicDrawPhaseAt (Verse.DrawPhase phase, UnityEngine.Vector3 drawLoc, System.Nullable`1[T] rotOverride, System.Boolean neverAimWeapon) [0x00003] in <d2f9716cc2ac4cda9c2a174cc147bf37>:0
at Verse.Pawn.DynamicDrawPhaseAt (Verse.DrawPhase phase, UnityEngine.Vector3 drawLoc, System.Boolean flip) [0x0000f] in <d2f9716cc2ac4cda9c2a174cc147bf37>:0
at Verse.Thing.DynamicDrawPhase (Verse.DrawPhase phase) [0x00017] in <d2f9716cc2ac4cda9c2a174cc147bf37>:0
at Verse.DynamicDrawManager.DrawDynamicThings () [0x0006f] in <d2f9716cc2ac4cda9c2a174cc147bf37>:0
at Verse.Map.MapUpdate () [0x000d4] in <d2f9716cc2ac4cda9c2a174cc147bf37>:0
at Verse.Game.UpdatePlay () [0x00049] in <d2f9716cc2ac4cda9c2a174cc147bf37>:0
at Verse.Root_Play.Update () [0x00032] in <d2f9716cc2ac4cda9c2a174cc147bf37>:0
UnityEngine.StackTraceUtility:ExtractStackTrace ()
(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.Log.Error_Patch1 (string)
Verse.Root_Play:Update ()

actually re-reading this it could also be the big and small mod but i am not sure.

I've been having this issue with the Pony and Cutebold mods where the ponies grab xenotypes from this and, as a result, they end up "broken" and invisible with the non-map background doing the crazy "Hall of Mirrors" thing described above. To fix it, I have to use Character Editor to set their xenotypes to the correct things or Baseliner to fix the graphical error. Not sure if this helps you track down what's going on!

Also experiencing this

Seems to be connected to the anthrofurs and how they affect the pawn heads. Pawn becomes visible if you characteredit the head to furskin head or any nonstandard pawn head type

I'll try to push a fix soon. IRL emergency stuff got in the way of doing that earlier.

Pushed, should be fixed. The head textures might be wrong sometimes but at least they should be able to join without errors now.

Thank you for looking into it! I haven't tested to see if it works, but I just wanted to say I really appreciate you looking into it. I really like the mod and you're the best for looking into this little bug.

I also had errors with the forbiden mod not working after adding this mod it seems to be causing errors with head textures once removed it did fix the error, sad cause i love this mod.
this is what i get and this is only with base RJW and this mod and required mods to work this is the error.

Error rendering pawn portrait: System.NullReferenceException: Object reference not set to an instance of an object
[Ref 162055B]
at Anthrosonae.PawnRenderNode_GraphicFor_Patch.Postfix (Verse.PawnRenderNode __instance, Verse.Pawn pawn, Verse.Graphic& __result) [0x00033] in <c387561ec1c645cbbd2ae156a17fde10>:0
at Verse.PawnRenderNode.GraphicFor (Verse.Pawn pawn) [0x0004f] in <630e2863bc9a4a3493f2eff01e3a9556>:0
- POSTFIX AnthrosonaeMod: Void Anthrosonae.PawnRenderNode_GraphicFor_Patch:Postfix(PawnRenderNode __instance, Pawn pawn, Graphic& __result)
at Verse.PawnRenderNode+<GraphicsFor>d__67.MoveNext () [0x00031] in <630e2863bc9a4a3493f2eff01e3a9556>:0
at Verse.PawnRenderNode.EnsureMaterialsInitialized () [0x0003b] in <630e2863bc9a4a3493f2eff01e3a9556>:0
at Rimworld_Animations.PawnRenderNode_GraphicVariants.EnsureMaterialsInitialized () [0x00042] in <3299370f5eec4147b2654192f5f0da1a>:0
at Verse.PawnRenderNode.EnsureInitialized (Verse.PawnRenderFlags defaultRenderFlagsNow) [0x00036] in <630e2863bc9a4a3493f2eff01e3a9556>:0
at Verse.PawnRenderNode.EnsureInitialized (Verse.PawnRenderFlags defaultRenderFlagsNow) [0x00091] in <630e2863bc9a4a3493f2eff01e3a9556>:0
at Verse.PawnRenderTree.EnsureInitialized (Verse.PawnRenderFlags defaultRenderFlagsNow) [0x00010] in <630e2863bc9a4a3493f2eff01e3a9556>:0
at Verse.PawnRenderer.RenderCache (Verse.Rot4 rotation, System.Single angle, UnityEngine.Vector3 positionOffset, System.Boolean renderHead, System.Boolean portrait, System.Boolean renderHeadgear, System.Boolean renderClothes, System.Collections.Generic.IReadOnlyDictionary`2[TKey,TValue] overrideApparelColor, System.Nullable`1[T] overrideHairColor, System.Boolean stylingStation) [0x00141] in <630e2863bc9a4a3493f2eff01e3a9556>:0
UnityEngine.StackTraceUtility:ExtractStackTrace ()
(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.Log.Error_Patch1 (string)
Verse.PawnRenderer:RenderCache (Verse.Rot4,single,UnityEngine.Vector3,bool,bool,bool,bool,System.Collections.Generic.IReadOnlyDictionary`2<RimWorld.Apparel, UnityEngine.Color>,System.Nullable`1<UnityEngine.Color>,bool)
RimWorld.PawnCacheRenderer:OnPostRender ()
RimWorld.PawnCacheRenderer:RenderPawn (Verse.Pawn,UnityEngine.RenderTexture,UnityEngine.Vector3,single,single,Verse.Rot4,bool,bool,bool,bool,UnityEngine.Vector3,System.Collections.Generic.IReadOnlyDictionary`2<RimWorld.Apparel, UnityEngine.Color>,System.Nullable`1<UnityEngine.Color>,bool)
RimWorld.PortraitsCache/PortraitParams:RenderPortrait (Verse.Pawn,UnityEngine.RenderTexture)
RimWorld.PortraitsCache:Get (Verse.Pawn,UnityEngine.Vector2,Verse.Rot4,UnityEngine.Vector3,single,bool,bool,bool,bool,System.Collections.Generic.IReadOnlyDictionary`2<RimWorld.Apparel, UnityEngine.Color>,System.Nullable`1<UnityEngine.Color>,bool,System.Nullable`1<Verse.PawnHealthState>)
RimWorld.ColonistBarColonistDrawer:DrawColonist (UnityEngine.Rect,Verse.Pawn,Verse.Map,bool,bool)
RimWorld.ColonistBar:ColonistBarOnGUI ()
RimWorld.MapInterface:MapInterfaceOnGUI_BeforeMainTabs ()
RimWorld.UIRoot_Play:UIRootOnGUI ()
(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.Root.OnGUI_Patch1 (Verse.Root)