SAP Message RU138 - Order & has no object reference

Diagnosis
The order does not refer to an object.

System Response
The system checks whether a structure explosion is possible for the
technical object (equipment or functional location). If a technicalobject has not been entered in the order, a structure explosion is notpossible.

Procedure
The function is only possible if the order refers to an object. You canuse an order maintenance transaction to enter an object reference.