How To Fix /IWBEP/CM_MED030 - Select a class instead of an interface

SAP Error Message - Details

• Message type: E = Error

• Message class: /IWBEP/CM_MED -

• Message number: 030

• Message text: Select a class instead of an interface

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.

Smart SAP Assistant

• What is the cause and solution for SAP error message /IWBEP/CM_MED030 - Select a class instead of an interface ?

  The SAP error message /IWBEP/CM_MED030 typically occurs in the context of SAP Gateway development, particularly when working with the OData services. This error indicates that an interface was selected when a class was expected. Here’s a breakdown of the cause, solution, and related information for this error:
  Cause:
  
  Incorrect Type Selection: The error arises when an interface is selected in a context where a class is required. In SAP Gateway, certain operations or configurations expect a concrete implementation (class) rather than an abstract definition (interface).
  Model Configuration Issues: This can happen during the configuration of the data model in the SAP Gateway service builder (transaction code SEGW), where the developer might have mistakenly chosen an interface instead of a class for a specific entity or data type.
  
  Solution:
  
  Check the Data Model: Go to the service builder (SEGW) and review the data model. Ensure that for the entity types and associations, you are using classes where required.
  Adjust the Implementation: If you have implemented methods for an OData service, ensure that you are implementing them in a class that extends the appropriate base class rather than an interface.
  Regenerate the Service: After making the necessary changes, regenerate the service to ensure that the changes are reflected in the OData service.
  Review the Service Implementation: Check the implementation of the service methods in the DPC (Data Provider Class) and MPC (Model Provider Class) to ensure that they are correctly referencing classes instead of interfaces.
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with transaction codes like SEGW (Service Builder) and SE80 (Object Navigator) for managing OData services.
  SAP Gateway Documentation: Refer to the official SAP Gateway documentation for best practices on defining and implementing OData services.
  Debugging: If the error persists, consider using the debugger to trace where the interface is being incorrectly referenced.
  Community and Support: Engage with the SAP Community or consult SAP Notes for similar issues and resolutions shared by other developers.
  
  By following these steps, you should be able to resolve the /IWBEP/CM_MED030 error and ensure that your OData service is correctly configured.