Exception in BreadthFirstTraverse: System.NullReferenceException: Object reference not set to an instance of an object
  at DoctorVanGogh.ReclaimReuseRecycle.Filter_Corpse.<DoesMatch>b__5_0 (DoctorVanGogh.ReclaimReuseRecycle.PackedThingDef pd) [0x00000] in <filename unknown>:0
  at System.Linq.Enumerable.Any[PackedThingDef] (IEnumerable`1 source, System.Func`2 predicate) [0x00000] in <filename unknown>:0
  at DoctorVanGogh.ReclaimReuseRecycle.Filter_Corpse.DoesMatch (Verse.Corpse corpse) [0x00000] in <filename unknown>:0
  at DoctorVanGogh.ReclaimReuseRecycle.Filter_Corpse.Matches (Verse.Thing t) [0x00000] in <filename unknown>:0
  at Verse.ThingFilter.Allows (Verse.Thing t) [0x00000] in <filename unknown>:0
  at RimWorld.Bill.IsFixedOrAllowedIngredient (Verse.Thing thing) [0x00000] in <filename unknown>:0
  at RimWorld.WorkGiver_DoBill+<TryFindBestBillIngredients>c__AnonStorey2B3.<>m__15B (Verse.Thing t) [0x00000] in <filename unknown>:0
  at RimWorld.WorkGiver_DoBill+<TryFindBestBillIngredients>c__AnonStorey2B3.<>m__15E (Verse.Region r) [0x00000] in <filename unknown>:0
  at Verse.RegionTraverser+BFSWorker.BreadthFirstTraverseWork (Verse.Region root, Verse.RegionEntryPredicate entryCondition, Verse.RegionProcessor regionProcessor, Int32 maxRegions, RegionType traversableRegionTypes) [0x00000] in <filename unknown>:0
  at Verse.RegionTraverser.BreadthFirstTraverse (Verse.Region root, Verse.RegionEntryPredicate entryCondition, Verse.RegionProcessor regionProcessor, Int32 maxRegions, RegionType traversableRegionTypes) [0x00000] in <filename unknown>:0
Verse.Log:Error(String)
Verse.RegionTraverser:BreadthFirstTraverse(Region, RegionEntryPredicate, RegionProcessor, Int32, RegionType)
RimWorld.WorkGiver_DoBill:TryFindBestBillIngredients(Bill, Pawn, Thing, List`1)
RimWorld.WorkGiver_DoBill:StartOrResumeBillJob_Patch0(Object, Pawn, IBillGiver)
RimWorld.WorkGiver_DoBill:JobOnThing(Pawn, Thing, Boolean)
RimWorld.WorkGiver_Scanner:HasJobOnThing(Pawn, Thing, Boolean)
PrisonLabor.HarmonyPatches.<>c__DisplayClass1_0:<CreatePredicate>b__0(Thing)
Verse.<ClosestThingReachable>c__AnonStorey5FB:<>m__BFD(Thing)
Verse.GenClosest:ClosestThing_Global(IntVec3, IEnumerable, Single, Predicate`1)
Verse.GenClosest:ClosestThingReachable(IntVec3, Map, ThingRequest, PathEndMode, TraverseParms, Single, Predicate`1, IEnumerable`1, Int32, Int32, Boolean, RegionType, Boolean)
ExpandedRoofing.ClosestThingReachableHelper:ClosestThingReachableWrapper(IntVec3, Map, ThingRequest, PathEndMode, TraverseParms, Single, Predicate`1, IEnumerable`1, Int32, Int32, Boolean, RegionType, Boolean)
RimWorld.JobGiver_Work:TryIssueJobPackage_Patch0(Object, Pawn, JobIssueParams)
Verse.AI.ThinkNode_PrioritySorter:TryIssueJobPackage(Pawn, JobIssueParams)
Verse.AI.ThinkNode_Priority:TryIssueJobPackage(Pawn, JobIssueParams)
Verse.AI.ThinkNode_Tagger:TryIssueJobPackage(Pawn, JobIssueParams)
Verse.AI.ThinkNode_Subtree:TryIssueJobPackage(Pawn, JobIssueParams)
Verse.AI.ThinkNode_Priority:TryIssueJobPackage(Pawn, JobIssueParams)
RimWorld.ThinkNode_Conditional:TryIssueJobPackage(Pawn, JobIssueParams)
Verse.AI.ThinkNode_Priority:TryIssueJobPackage(Pawn, JobIssueParams)
Verse.AI.Pawn_JobTracker:DetermineNextJob(ThinkTreeDef&)
Verse.AI.Pawn_JobTracker:TryFindAndStartJob()
Verse.AI.Pawn_JobTracker:EndCurrentJob_Patch1(Object, JobCondition, Boolean)
Verse.AI.Pawn_JobTracker:JobTrackerTick()
Verse.Pawn:Tick()
Verse.TickList:Tick()
Verse.TickManager:DoSingleTick()
Verse.TickManager:TickManagerUpdate()
Verse.Game:UpdatePlay()
Verse.Root_Play:Update()