The product code is either does not exist or not updated successfully. Please perform the following:
Step 1 - Confirm via Report
Please confirm the new product has been added either through the Inventory report (F2, L3 - Reports, L2 - Inventory) or go to your SC / Merchant website - Master Stock Maintenance.
Step 2 - Perform Files Update at the terminal
Once you have confirmed the product has been added into the Master Stock, you need to do Files Update at the terminal. Press F2, L2 - Files Update, L1- Update.
Note - every time you have updated product information either via the terminal or website, you need to perform Files Update process (i.e. Step 2) at the terminal.