I'm having the same issue now...

Looks like there is an item with missing icon.
As far as i can tell, the vanilla method to draw icon is failing.
I'll add some error handling to let it skip icons if they are missing

Sorry for late response, i was not notified about a created thread

Recent update broke trade UI for me and I'm getting no trader inventory and the following error messages:

JobDriver threw exception in toil MakeNewToils's initAction for pawn Brandon driver=JobDriver_TradeWithPawn (toilIndex=1) driver.job=(TradeWithPawn (Job_2591507) A=Thing_Human99139)
System.TypeLoadException: Could not resolve type with token 0100008d (from typeref, class/assembly Verse.IWindowDrawing, Assembly-CSharp, Version=1.5.8839.705, Culture=neutral, PublicKeyToken=null)
at DynamicTradeInterface.Patches.Dialog_TradePatches.Prefix (RimWorld.Dialog_Trade __instance, System.Boolean ___giftsOnly) [0x0000c] in <1fe643ef8ccc4c90b493f70cc883d2cd>:0
at (wrapper dynamic-method) RimWorld.Dialog_Trade.RimWorld.Dialog_Trade.PostOpen_Patch2(RimWorld.Dialog_Trade)
at Verse.WindowStack.Add (Verse.Window window) [0x0003a] in <cd7169108ea74757aa50c5b33d275c15>:0
at RimWorld.JobDriver_TradeWithPawn+<>c__DisplayClass3_0.<MakeNewToils>b__1 () [0x00035] in <cd7169108ea74757aa50c5b33d275c15>: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_Patch2 (Verse.Pawn,string,System.Exception,Verse.AI.JobDriver)
Verse.AI.JobDriver:TryActuallyStartNextToil ()
Verse.AI.JobDriver:ReadyForNextToil ()
Verse.AI.JobDriver:Notify_PatherArrived ()
Verse.AI.Pawn_PathFollower:PatherArrived ()
(wrapper dynamic-method) Verse.AI.Pawn_PathFollower:Verse.AI.Pawn_PathFollower.TryEnterNextPathCell_Patch1 (Verse.AI.Pawn_PathFollower)
(wrapper dynamic-method) Verse.AI.Pawn_PathFollower:Verse.AI.Pawn_PathFollower.PatherTick_Patch3 (Verse.AI.Pawn_PathFollower)
(wrapper dynamic-method) Verse.Pawn:Verse.Pawn.Tick_Patch2 (Verse.Pawn)
Verse.TickList:Tick ()
(wrapper dynamic-method) Verse.TickManager:Verse.TickManager.DoSingleTick_Patch4 (Verse.TickManager)
Verse.TickManager:TickManagerUpdate ()
(wrapper dynamic-method) Verse.Game:Verse.Game.UpdatePlay_Patch1 (Verse.Game)
(wrapper dynamic-method) Verse.Root_Play:Verse.Root_Play.Update_Patch1 (Verse.Root_Play)



AND

Exception filling window for RimWorld.Dialog_Trade: System.NullReferenceException: Object reference not set to an instance of an object
at RimWorld.Dialog_Trade.FillMainRect (UnityEngine.Rect mainRect) [0x00006] in <cd7169108ea74757aa50c5b33d275c15>:0
at (wrapper dynamic-method) RimWorld.Dialog_Trade.RimWorld.Dialog_Trade.DoWindowContents_Patch1(RimWorld.Dialog_Trade,UnityEngine.Rect)
at Verse.Window.InnerWindowOnGUI (System.Int32 x) [0x001d3] in <cd7169108ea74757aa50c5b33d275c15>:0
UnityEngine.StackTraceUtility:ExtractStackTrace ()
(wrapper dynamic-method) Verse.Log:Verse.Log.Error_Patch3 (string)
Verse.Window:InnerWindowOnGUI (int)
UnityEngine.GUI:CallWindowDelegate (UnityEngine.GUI/WindowFunction,int,int,UnityEngine.GUISkin,int,single,single,UnityEngine.GUIStyle)


Disabling the mod returns normal vanilla trade functionality with the trader's inventory intact.