@Bolt. All that means is that you have specified a path that does not exist in the Joomla root directory. When you put a path in your Joomla root with files to list it will work. Make sure you spelt it correctly with exact letter case.
For example, if you files are located in http://aabraga.clientes.eurotux.com/oldsite/informacao/impressos, then you should put “oldsite” as the parent folder and “informacao/impressos” as your Listing location.