Exception in RimWorld.ThinkNode_Priority_GetJoy TryIssueJobPackage: System.NullReferenceException: Object reference not set to an instance of an object [Ref 1249AA50] at Verse.BookUtility.IsValidBook (Verse.Thing thing, Verse.Pawn pawn) [0x00011] in <91ef6de66e7b4ba2839be0ab7f01fedf>:0 at Verse.BookUtility+<>c__DisplayClass10_0.<TryGetRandomBookToRead>b__2 (Verse.Book thing) [0x00000] in <91ef6de66e7b4ba2839be0ab7f01fedf>:0 at System.Linq.Enumerable+WhereEnumerableIterator`1[TSource].MoveNext () [0x00037] in <351e49e2a5bf4fd6beabb458ce2255f3>:0 at System.Collections.Generic.List`1[T].InsertRange (System.Int32 index, System.Collections.Generic.IEnumerable`1[T] collection) [0x000db] in <eae584ce26bc40229c1b1aa476bfa589>:0 at System.Collections.Generic.List`1[T].AddRange (System.Collections.Generic.IEnumerable`1[T] collection) [0x00000] in <eae584ce26bc40229c1b1aa476bfa589>:0 at Verse.BookUtility.TryGetRandomBookToRead (Verse.Pawn pawn, Verse.Book& book) [0x000a5] in <91ef6de66e7b4ba2839be0ab7f01fedf>:0 at RimWorld.JoyGiver_Read.TryGiveJob (Verse.Pawn pawn) [0x00000] in <91ef6de66e7b4ba2839be0ab7f01fedf>:0 at RimWorld.JobGiver_GetJoy.TryGiveJobFromJoyGiverDefDirect (RimWorld.JoyGiverDef def, Verse.Pawn pawn) [0x00006] in <91ef6de66e7b4ba2839be0ab7f01fedf>:0 at RimWorld.JobGiver_GetJoy.TryGiveJob (Verse.Pawn pawn) [0x0015d] in <91ef6de66e7b4ba2839be0ab7f01fedf>:0 at Verse.AI.ThinkNode_JobGiver.TryIssueJobPackage (Verse.Pawn pawn, Verse.AI.JobIssueParams jobParams) [0x00000] in <91ef6de66e7b4ba2839be0ab7f01fedf>:0 at Verse.AI.ThinkNode_Priority.TryIssueJobPackage (Verse.Pawn pawn, Verse.AI.JobIssueParams jobParams) [0x00022] in <91ef6de66e7b4ba2839be0ab7f01fedf>:0 UnityEngine.StackTraceUtility:ExtractStackTrace () (wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.Log.Error_Patch5 (string) Verse.AI.ThinkNode_Priority:TryIssueJobPackage (Verse.Pawn,Verse.AI.JobIssueParams) Verse.AI.ThinkNode_PrioritySorter:TryIssueJobPackage (Verse.Pawn,Verse.AI.JobIssueParams) Verse.AI.ThinkNode_Priority:TryIssueJobPackage (Verse.Pawn,Verse.AI.JobIssueParams) Verse.AI.ThinkNode_Tagger:TryIssueJobPackage (Verse.Pawn,Verse.AI.JobIssueParams) Verse.AI.ThinkNode_Priority:TryIssueJobPackage (Verse.Pawn,Verse.AI.JobIssueParams) Verse.AI.ThinkNode_Conditional:TryIssueJobPackage (Verse.Pawn,Verse.AI.JobIssueParams) Verse.AI.ThinkNode_Priority:TryIssueJobPackage (Verse.Pawn,Verse.AI.JobIssueParams) (wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.AI.Pawn_JobTracker.DetermineNextJob_Patch1 (Verse.AI.Pawn_JobTracker,Verse.ThinkTreeDef&,bool) (wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Glue:AbiFixup<Verse.AI.ThinkResult Verse.AI.Pawn_JobTracker:DetermineNextJob(Verse.ThinkTreeDef&, System.Boolean),Verse.AI.ThinkResult Verse.AI.Pawn_JobTracker.DetermineNextJob_Patch1(Verse.AI.Pawn_JobTracker, Verse.ThinkTreeDef&, System.Boolean)> (Verse.AI.Pawn_JobTracker,Verse.AI.ThinkResult&,Verse.ThinkTreeDef&,bool) Verse.AI.Pawn_JobTracker:TryFindAndStartJob () (wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.AI.Pawn_JobTracker.EndCurrentJob_Patch1 (Verse.AI.Pawn_JobTracker,Verse.AI.JobCondition,bool,bool) Verse.AI.Pawn_JobTracker:JobTrackerTick () (wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.Pawn.Tick_Patch1 (Verse.Pawn) Verse.TickList:Tick () (wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.TickManager.DoSingleTick_Patch4 (Verse.TickManager) Verse.TickManager:TickManagerUpdate () (wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.Game.UpdatePlay_Patch2 (Verse.Game) (wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.Root_Play.Update_Patch1 (Verse.Root_Play)