Delivery &1, item &2: Loading quantities inconsistent

What causes this issue?

You have confirmed a warehouse task for loading for an outbound delivery
order. However, the change in data in the outbound delivery order is not
allowed due to an item split in that order.
This may be due to one of the following reasons:
If you have already loaded a delivery quantity for the main item of the
item split, you are not allowed to load any delivery quantities for
subitems of the item split.
If you have already loaded a delivery quantity for the subitem of the
item split, you are not allowed to load any delivery quantities for the
main item of the item split.
If you have not yet loaded delivery quantities for items of an item
split (that is, neither for the main item nor for the subitem), you are
then allowed to load quantities for the subitem only.

System Response

The system sets the status of the delivery item with the inadmissible
loading quantities to <ZK>Incorrect</>.
The system does not reset the status of the delivery item to <ZK>Correct
</>until the error situation has been rectified.

How to fix this error?

If you have already loaded delivery quantities for the main item and the
subitem, you must either:
Reverse the loading for (that is, unload) the subitem and then reverse
the item split for this subitem, or
Reverse the loading for the main item
If you have already loaded delivery quantities for a subitem and if
loading is now to take place for the main item, you must first split the
quantities to be loaded via an item split to a subitem.
Proceed in exactly the same way if you have already performed a split
but the delivery quantities have not yet been loaded for the subitems.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.