Issues with Payables Invoices Open Interface Import process?

To assist in the resolution of the issues arising in the Payables Invoices Open Interface Import process, two different Master Notes have been created in My Oracle Support. They include a specific explanation of the Open Interface Import process, tables and packages involved in the process, instructions to complete the process and also a troubleshooting guide classified by the known issues arising during the process.
Here we have the detail of these Master Notes:
   1) Note:1311923.1 - R12: Master Note: APXIIMPT - Payables Open Interface Import - Functional Overview
   2) Note:1311932.1 - R12: Master Note: APXIIMPT - Payables Open Interface Import - Troubleshooting