Go to Setup > Settings and under the Inventory menu click on the Product Pack Defaults link.

The activation option will show, check the box to enable the product pack defaults.

Pay special attention to the second option:

Choosing "Will": the system will save the pack specifications for items that are being entered into the system for the first time. This means that whenever there is a product without pack specifications under the Setup > Products > Default Product Packs screen, the system will save the pack information used on any order where the product was entered for the first time.
Choosing "Will not": the system will not save the product packs values that are being entered for the first time. In this case, the pack specifications will have to be entered directly through the Setup > Products > Default Product Packs screen.

The system will now load the product pack information when creating Prebooks and Standing Orders.

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