Error when equipping shield if one is already equipped.

[SickBoyWi]

If I have a pawn with a shield equipped, and try to equip a different one, I get this error:

JobDriver threw exception in initAction for pawn Rogrum driver=JobDriver_Equip (toilIndex=1) driver.job=(Equip (Job_87) A=Thing_RH_TET_Dwarf_ShieldMid58557) lastJobGiver=Verse.AI.ThinkNode_QueuedJob
System.NullReferenceException: Object reference not set to an instance of an object
at PawnShields.HarmonyPatches.EquipmentTracker_GetPawn (object) <0x0001e>
at PawnShields.HarmonyPatches.Patch_Pawn_EquipmentTracker_MakeRoomFor (Verse.Pawn_EquipmentTracker,Verse.ThingWithComps&) <0x00092>
at (wrapper dynamic-method) Verse.Pawn_EquipmentTracker.MakeRoomFor_Patch1 (object,Verse.ThingWithComps) <0x00152>
at Verse.AI.JobDriver_Equip/c__Iterator0.<>m__0 () <0x000f9>
at Verse.AI.JobDriver.TryActuallyStartNextToil () <0x0071f>

Verse.Log:Error(String, Boolean)
Verse.AI.JobUtility:TryStartErrorRecoverJob(Pawn, String, Exception, JobDriver)
Verse.AI.JobDriver:TryActuallyStartNextToil()
Verse.AI.JobDriver:ReadyForNextToil()
Verse.AI.JobDriver:Notify_PatherArrived()
Verse.AI.Pawn_PathFollower:PatherArrived()
Verse.AI.Pawn_PathFollower:TryEnterNextPathCell()
Verse.AI.Pawn_PathFollower:PatherTick()
Verse.Pawn:Tick_Patch1(Object)
Verse.TickList:Tick()
Verse.TickManager:DoSingleTick()
Verse.TickManager:TickManagerUpdate()
Verse.Game:UpdatePlay()
Verse.Root_Play:Update()

I traced it back through your source code, and here's the function that fails. The only thing that can be null there seems to be 'pawnField_Pawn_EquipmentTracker'.

        public static Pawn EquipmentTracker_GetPawn(object instance)
        {
            return (Pawn)pawnField_Pawn_EquipmentTracker.GetValue(instance);
        }

Is this a known issue? I don't see an open issue for it. Any thoughts?