Inventor rule does not work anymore

[morrenengineering]

Dear members,

I had this rule like under, but it does not work since the last update. Can someone help me

This error is given

Error in rule: bevestigingsmaterialen-OFF, in document: C152.iam

Object reference not set to an instance of an object.

Dim assemblyDef As AssemblyComponentDefinition = ThisDoc.Document.ComponentDefinition

Dim occ As Inventor.ComponentOccurrence
For Each occ In assemblyDef.Occurrences.AllLeafOccurrences
    Dim refDoc As PartDocument = occ.Definition.Document
    
    Dim customPropSet As PropertySet
    customPropSet = refDoc.PropertySets.Item("Inventor User Defined Properties")

	Dim weightProp As Inventor.Property
	weightProp = Nothing
	Try
		weightProp = customPropSet.Item("art")
    Catch ex As Exception
	End Try		
    
    
    weightVal = weightProp.Value
        
        If weightVal = "BEV" Then
            occ.Visible = False
        Else
            occ.Visible = True
        End If

Next

[JelteDeJong · Accepted solution]

i expect that there is an part without a iProperty "art". try this rule and you will know for sure:

Dim assemblyDef As AssemblyComponentDefinition = ThisDoc.Document.ComponentDefinition

Dim occ As Inventor.ComponentOccurrence
For Each occ In assemblyDef.Occurrences.AllLeafOccurrences
    Dim refDoc As PartDocument = occ.Definition.Document
    
    Dim customPropSet As PropertySet = refDoc.PropertySets.Item("Inventor User Defined Properties")

	Dim weightProp As Inventor.Property
	weightProp = Nothing
	Try
		weightProp = customPropSet.Item("art")
    Catch ex As Exception
		MsgBox("Could not find iProperty 'art' in part " & refDoc.DisplayName)
	End Try		
    If weightProp Is Nothing Then continue For
    
    weightVal = weightProp.Value
        
    If weightVal = "BEV" Then
        occ.Visible = False
    Else
        occ.Visible = True
    End If
Next