Partial confirmation: 'Fixed Date/Quantity' checkbox is set for item &1

What causes this issue?

You have manually reduced the confirmed quantity for stock transport
order item &V1& . However, this stock transport order belongs to a
document type for which the <ZK>ATP Conf. MRP</> checkbox has been
selected in Customizing for <ZK>Purchasing</>. If this checkbox is
selected, the total confirmed quantity in documents has to be equal to
the total requested quantity.

System Response

Since due to your manual changes the total confirmed quantity is less
than the total requested quantity, the system selects the <ZK>Fixed
Date/Quantity</> checkbox in the order item.
Therefore this item is only considered in future BOP runs if the
<ZK>Consider Fixed Confirm.</> checkbox is selected in your BOP filter
settings. BOP tries to achieve the manually set confirmation date and
quantity rather than the original date and quantity.

How to fix this error?

If you want future BOP runs to be able to improve the comfirmation time
of this item, add an additional confirmation line with quantity &V2&
before saving.

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.