Message type: E = Error
Message class:  IW - Order Processing 
Message number: 303
Message text: No reference object selected
You requested the selection of an <GL:assembly>assembly</> by means of
the structure list or structure graphic, but did not select an assembly.
The system issues an error message and will not allow you to continue with this transaction until the error is resolved.
The system did not change the original assembly in the operation.
Error message extract from SAP system. Copyright SAP SE.
The SAP error message IW303 "No reference object selected" typically occurs in the context of maintenance processing, particularly when trying to create or process a maintenance order or notification. This error indicates that the system expects a reference object (like a functional location, equipment, or another maintenance order) to be selected or specified, but none has been provided. Causes: Missing Reference Object: The most common cause is that the user has not selected a reference object when trying to create or process a maintenance order or notification. Incorrect Transaction: The transaction being used may not be appropriate for the type of reference object being worked with. Authorization Issues: Sometimes, the user may not have the necessary authorizations to view or select the reference objects.
Configuration Issues: There may be configuration settings in the SAP system that are not set up correctly, leading to this error. Solutions: Select a Reference Object: Ensure that you have selected a valid
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