Unable to apply finish to multiple of the same part within an assembly

[mitchELAHB]

Hi guys,

I have a script I use to apply a powder coat finish to all faces in an assembly, but it fails when I have multiple of the same part within it. This is a problem as most of the assemblies I design are held together with fasteners, which are all the same part. Here is the script that I'm using:

Option Explicit On
Sub Main
	
	Dim oInvApp As Inventor.Application = ThisApplication
	Dim oADoc As AssemblyDocument = TryCast(ThisDoc.FactoryDocument, Inventor.AssemblyDocument)
	If oADoc Is Nothing Then Return
	Dim oADef As AssemblyComponentDefinition = oADoc.ComponentDefinition

	'set list of components to skip
	Dim oSkipList As New ArrayList
	oSkipList.Clear 
'	oSkipList.Add("20110") 'add parts to skip here
'	oSkipList.Add("20224")
	
	Dim oFaceColl As Inventor.FaceCollection
	
	For Each oComponent In oADoc.ComponentDefinition.Occurrences
		
		If oComponent.Suppressed = True Then Continue For
		If TypeOf oComponent.Definition Is VirtualComponentDefinition Then Continue For
		
		GetFaces(oComponent, oFaceColl, oSkipList)
		
	Next
	
	Dim oFinishColour = "Manor Red" 
	Dim oAppearance As Object = oADoc.AppearanceAssets.Item(oFinishColour)
	
	Dim oFinishFeats As FinishFeatures = oADef.Features.FinishFeatures
	Dim oFinishDef As FinishDefinition = oFinishFeats.CreateFinishDefinition(oFaceColl, FinishTypeEnum.kMaterialCoatingFinishType, "Powder Coat", oAppearance)
	Dim oFinishFeat As FinishFeature = oFinishFeats.Add(oFinishDef)
	
End Sub


Function GetFaces(occ As Inventor.ComponentOccurrence, Optional ByRef faceColl As Inventor.FaceCollection = Nothing, Optional oSkipList As ArrayList = Nothing) As Inventor.FaceCollection
	
	If (occ Is Nothing) OrElse occ.Suppressed Then Return Nothing
	If TypeOf occ.Definition Is VirtualComponentDefinition Then Return Nothing
	
	Dim oOccName As String = Split(occ.Name, ":")(0)
	If oSkipList.Contains(oOccName) Then Return Nothing
	
	If faceColl Is Nothing Then faceColl = ThisApplication.TransientObjects.CreateFaceCollection()
		
	For Each oBody As SurfaceBody In occ.SurfaceBodies
		For Each oFace As Face In oBody.Faces
			faceColl.Add(oFace)
		Next 'oFace
	Next 'oBody
	
	If occ.SubOccurrences IsNot Nothing AndAlso occ.SubOccurrences.Count > 0 Then
		For Each oSubOcc As Inventor.ComponentOccurrence In occ.SubOccurrences
			GetFaces(oSubOcc, faceColl, oSkipList)
		Next 'oSubOcc
	End If
	
	Return faceColl
	
End Function

The code fails on the line:

Dim oFinishDef As FinishDefinition = oFinishFeats.CreateFinishDefinition(oFaceColl, FinishTypeEnum.kMaterialCoatingFinishType, "Powder Coat", oAppearance)

 With the error "The parameter is incorrect. (0x80070057 (E_INVALIDARG))"

At the moment I have made made the function skip these parts which are used multiple times, by adding their part numbers to an array. This is not ideal as the finish does not include the fasteners, and going forward I want to use this code for larger assemblies that contain multiples of parts that are manufactured in house. 

Does anyone know a way to get this to work, or is it a bug? I'm running Inventor 2025.3.1. I have tried on multiple machines and got the same error.