Old School Combine with Custom Error

(myFolderPath as text) as table => 
let
    Source = Folder.Files(myFolderPath),
    #"Removed Other Columns" = Table.SelectColumns(Source,{"Content"}),
    Content = #"Removed Other Columns"[Content],
    Custom1 = Binary.Combine(Content),
    Custom2 = Csv.Document (Custom1)
  in
    try Custom2 otherwise error [Reason="Transformation Exception", Message="The data that you're trying to combine does not appear to be a flat file", Detail="Make sure that you're only combining csv, txt or other flat files"]