How To Fix /IWFND/MED_SVC_MU_LA028 - Reference type for ID '&1' not declared

/IWFND/MED_SVC_MU_LA028 - Overview

• Message type: E = Error

• Message class: /IWFND/MED_SVC_MU_LA -

• Message number: 028

• Message text: Reference type for ID '&1' not declared

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

Unfortunately, there isn't any extra information in this error notice.

What else can you do?

First, use our AnswerBot below to get a possible cause and solution (requires a premium subscription).

Also, review the in-depth Common Questions & Answers listed below; you could discover a solution there or be able to connect with others who have faced similar challenges.

You can also try searching the SAP support portal (support.sap.com) but you need a special user ID to access it. It is possible that an SAP support note exists that provides additional details about the mistake or even steps for fixing it.

/IWFND/MED_SVC_MU_LA028 - Details

• The SAP error message /IWFND/MED_SVC_MU_LA028 Reference type for ID '&1' not declared typically occurs in the context of SAP Gateway and OData services. This error indicates that the system is unable to find a reference type for the specified ID, which can happen for several reasons.
  Causes:
  
  Missing Reference Type Declaration: The reference type that is being called in the OData service is not declared in the metadata.
  Incorrect Service Registration: The OData service may not be properly registered or activated in the SAP Gateway.
  Model Issues: There may be issues with the data model or the way entities are defined in the service.
  Transport Issues: If the service was transported from one system to another, the reference types may not have been included in the transport.
  Versioning Issues: If there are multiple versions of the service, the reference type may exist in one version but not in another.
  
  Solutions:
  
  Check Metadata: Verify that the reference type is