Goods issue has not yet been posted for selected delivery &

What causes this issue?

The delivery that you selected has not yet been posted to
<DS:GLOS.goods_issue>goods issue</>.
Please keep in mind that, in the delivery schedule, the system
automatically sets the cumulative received quantity to the cumulative
delivered quantity of the last delivery you selected if the
<LS>cumulative received quantity</> field is not filled. This occurs
regardless of whether the delivery is actually posted to goods issue.
This results in the open quantities being redetermined due to the
delivered quantity of the selected delivery.

How to fix this error?

Assign deliveries that have not yet been posted to goods issue only if
goods issue has taken place physically and if the customer has received
the goods. Otherwise, the system will not be able to give a correct
representation of the delivery situation.
The system does not take into account correction deliveries when
checking for GI posting.

Error message extract from SAP system. Copyright SAP SE.