User receives the following error when creating a new commodity code under Commodity Code Manager > Commodity Codes > Create New:

This key value already exist. Duplicates are not allowed

You must re-activate the commodity code via import task with the following steps:

1. Click Manage > Core Administration.
2. Click Site Manager > Data Import / Export.
3. Use Import System Commodity Codes task - Load operation

The commodity code already exists in the system, it is just inactive.

It's recommended to have a backup file of the export task before running an import task to update existing data.

Core Procurement > Core Administration > Commodity codes