Costs of purchase order &V1& item &V2& cannot be distributed

What causes this issue?

Costs and payments for purchase order &V1&, item &V2& cannot be
distributed since the status of at least one of the assigned WBS
elements or breakpoints does not allow this.

System Response

The program ignores the costs and payments connected with this order
item.

How to fix this error?

Check the status of the WBS elements and breakpoints assigned to the
purchase order. You can display these assigned objects with transaction
PEG03.

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.