Dim fs As Object
Set fs = CreateObject("Scripting.FileSystemObject")
Dim folder As Object
Set folder = fs.GetFolder(ThisWorkbook.path)
Dim file As Object
Dim sKey As String
Dim fileDate As Date

For Each file In folder.Files
If file.DateCreated > fileDate Then
fileDate = file.DateCreated
'sKey = file.Name //  this works but I want next line instead
sKey = file.BuiltinDocumentProperties("Keywords").Value  //  Error is here
End If
Next file

MsgBox ThisWorkbook.BuiltinDocumentProperties("Keywords").Value

Dim wb As Workbook
Set wb = Workbooks.Open(filename:=file.Name, ReadOnly:=True)
skey = wb.BuiltinDocumentProperties("Keywords").Value
wb.Close (False)