How To Fix /IWBEP/CM_V4_COS201 - Invalid navigation property name '&1' in expand expression

SAP Error Message - Details

• Message type: E = Error

• Message class: /IWBEP/CM_V4_COS -

• Message number: 201

• Message text: Invalid navigation property name '&1' in expand expression

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_V4_COS201 - Invalid navigation property name '&1' in expand expression ?

  The SAP error message /IWBEP/CM_V4_COS201 Invalid navigation property name '&1' in expand expression typically occurs in the context of OData services when there is an issue with the navigation properties specified in an $expand query option. This error indicates that the specified navigation property name is not valid or does not exist in the OData model.
  Cause:
  
  Incorrect Navigation Property Name: The name provided in the $expand query does not match any of the defined navigation properties in the OData service's metadata.
  Model Changes: If the OData model has been changed (e.g., properties added or removed) and the client application is using an outdated version of the model, it may reference non-existent properties.
  Case Sensitivity: OData is case-sensitive, so a mismatch in the case of the navigation property name can lead to this error.
  Service Metadata Issues: The OData service may not be properly exposing the navigation properties due to configuration issues or errors in the service implementation.
  
  Solution:
  
  Check Navigation Property Names: Verify the navigation property names in the OData service's metadata (usually accessible via the $metadata endpoint). Ensure that the name used in the $expand query matches exactly.
  Update Client Application: If the OData model has changed, ensure that the client application is updated to use the latest version of the model.
  Correct Case Sensitivity: Ensure that the navigation property names are used with the correct case as defined in the OData service.
  Review Service Implementation: If you are developing or maintaining the OData service, check the implementation to ensure that all navigation properties are correctly defined and exposed.
  Test with Simple Queries: Start with simpler queries to isolate the issue. For example, try querying without $expand or with a known valid navigation property to see if the service responds correctly.
  
  Related Information:
  
  OData Documentation: Familiarize yourself with the OData protocol and how navigation properties work. The official OData documentation can provide insights into best practices and common pitfalls.
  SAP Gateway: If you are using SAP Gateway, check the transaction codes like /IWFND/MAINT_SERVICE to manage and maintain OData services.
  Debugging Tools: Use tools like Postman or SAP Gateway Client to test OData queries and inspect responses, which can help in identifying issues with the query structure.
  
  By following these steps, you should be able to resolve the error and successfully use the $expand functionality in your OData queries.