Goods issue date item & not within &-& QS &

DEFINE &QS& = '<GL:quantity_schedule>quantity schedule</>'

What causes this issue?

The <DS:GLOS.goods issue date>date</> entered is outside the validity
period of the &QS& for the item(s).

System Response

The system uses the goods issue date to update the requested delivered
quantity in the relevant scheduling line of the &QS&.

How to fix this error?

Enter a date within the validity period of the &QS&, or remove item(s)
from the delivery. Use a valid goods issue (GI) date in a separate
<DS:GLOS.delivery>delivery</> for the items you removed.

Error message extract from SAP system. Copyright SAP SE.