Delivery was distributed, therefore display only

What causes this issue?

The delivery was distributed, meaning that processing occurs in another
system. The report back has not yet been received.

System Response

Since no changes can be made to the delivery, the display mode is
activated.

How to fix this error?

Changes in the delivery can only be made in the respective system.
Limited changes are possible after the report back, but they have no
affect on the distribution.

Error message extract from SAP system. Copyright SAP SE.