Exception ticking BB: System.ArgumentNullException: Argument cannot be null.
Parameter name: type
at System.Activator.CheckType (System.Type) <0x0005d>
at System.Activator.CreateInstance (System.Type,bool) <0x00013>
at System.Activator.CreateInstance (System.Type) <0x00012>
at Verse.ThingMaker.MakeThing (Verse.ThingDef,Verse.ThingDef) <0x00214>
at RimWorld.Frame.CompleteConstruction (Verse.Pawn) <0x002f3>
at RimWorld.JobDriver_ConstructFinishFrame/<MakeNewToils>c__Iterator0/<MakeNewToils>c__AnonStorey1.<>m__1 () <0x001ef>
at (wrapper dynamic-method) Verse.AI.JobDriver.DriverTick_Patch1 (object) <0x002ba>
at Verse.AI.Pawn_JobTracker.JobTrackerTick () <0x00242>
at Verse.Pawn.Tick () <0x00155>
at Verse.TickList.Tick () <0x002c6>

Verse.Log:Error(String)
Verse.TickList:Tick()
Verse.TickManager:DoSingleTick()
Verse.TickManager:TickManagerUpdate()
Verse.Game:UpdatePlay()
Verse.Root_Play:Update()