once the pawn is finished reading, it gets dropped onto the ground and doesn't do anything

JobDriver threw exception in toil unnamed's initAction for pawn R-1 driver=JobDriver_ReadBook (toilIndex=7) driver.job=(VBE_ReadBook (Job_384664) A=Thing_Human4211 B=Thing_VBE_Map88442 C=Thing_DiningChair44432)
System.NullReferenceException: Object reference not set to an instance of an object
at VanillaBooksExpanded.MapItem.UnlockQuest (Verse.Pawn pawn) [0x00160] in <c9efb248f3b74e129d100ea710d3f425>:0
at VanillaBooksExpanded.JobDriver_ReadBook.<MakeNewToils>b__7_5 () [0x0004f] in <c9efb248f3b74e129d100ea710d3f425>:0
at Verse.AI.JobDriver.TryActuallyStartNextToil () [0x001b0] in <cd7169108ea74757aa50c5b33d275c15>:0
UnityEngine.StackTraceUtility:ExtractStackTrace ()
(wrapper dynamic-method) Verse.Log:Verse.Log.Error_Patch3 (string)
(wrapper dynamic-method) Verse.AI.JobUtility:Verse.AI.JobUtility.TryStartErrorRecoverJob_Patch1 (Verse.Pawn,string,System.Exception,Verse.AI.JobDriver)
Verse.AI.JobDriver:TryActuallyStartNextToil ()
Verse.AI.JobDriver:ReadyForNextToil ()
VanillaBooksExpanded.JobDriver_ReadBook:<MakeNewToils>b__7_1 ()
(wrapper dynamic-method) Verse.AI.JobDriver:Verse.AI.JobDriver.DriverTick_Patch0 (Verse.AI.JobDriver)
Verse.AI.Pawn_JobTracker:JobTrackerTick ()
Verse.Pawn:Tick ()
Verse.TickList:Tick ()
(wrapper dynamic-method) Verse.TickManager:Verse.TickManager.DoSingleTick_Patch3 (Verse.TickManager)
Verse.TickManager:TickManagerUpdate ()
(wrapper dynamic-method) Verse.Game:Verse.Game.UpdatePlay_Patch1 (Verse.Game)
Verse.Root_Play:Update ()