Stock differences for object & could not be assigned

What causes this issue?

Stock differences for replenishment element &V1& could not be assigned.

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

System Response

The costs for the replenishment element cannot be assigned completely
during a cost distribution run or cannot be billed in cost-related
billing.

How to fix this error?

Create a WBS element for the <DS:TRAN.PEG04>assignemnt of stock
differences</>.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.