Apple Configurator 1.2.1: "The spreadsheet provided has redemption codes for (null)" message when importing spreadsheet

When importing a Volume Purchase Plan (VPP) spreadsheet into Apple Configurator 1.2.1, you may see this message, where Application is the name of the application for which you are importing codes: The spreadsheet provided has redemption codes for "(null)." Please provide a spreadsheet with codes for "Application."

Resolution

Update to Apple Configurator 1.3.