There are a number of “child” windows opened from the main Purchase Order Entry window, and a PO cannot be saved until they are all closed. Auto-Close Child Windows will automatically close any of these open windows when the Save button is clicked on Purchase Order Entry.
Navigation: Tools >> Setup >> Company >> Setup GP PowerPack
Mark the box next to TWK-POP: Auto-Close child windows, then click DONE.
The feature will be enabled for the current user. Other users must restart their Dynamics GP client to enable this feature.