How To Fix /IWFND/CM_MGW537 - eTag handling not supported for http method '&1'

SAP Error Message - Details

• Message type: E = Error

• Message class: /IWFND/CM_MGW -

• Message number: 537

• Message text: eTag handling not supported for http method '&1'

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 /IWFND/CM_MGW537 - eTag handling not supported for http method '&1' ?

  The SAP error message /IWFND/CM_MGW537 eTag handling not supported for http method '&1' typically occurs in the context of SAP Gateway services when there is an issue with the handling of eTags for specific HTTP methods. This error indicates that the eTag functionality, which is used for caching and managing resource versions, is not supported for the HTTP method being used in the request.
  Cause:
  The error is caused by the following scenarios:
  
  Unsupported HTTP Method: The HTTP method being used (e.g., POST, PUT, DELETE) does not support eTag handling. eTags are generally used with GET requests to manage caching and conditional requests.
  Service Configuration: The OData service may not be configured to handle eTags for the specific operation being performed.
  Incorrect Client Implementation: The client making the request may be incorrectly attempting to use eTags with an unsupported method.
  
  Solution:
  To resolve this error, consider the following steps:
  
  
  Check HTTP Method: Ensure that you are using the correct HTTP method for the operation you intend to perform. For example, if you are trying to retrieve data, use GET; for creating data, use POST; for updating, use PUT; and for deleting, use DELETE.
  
  
  Review Service Implementation: If you are developing or maintaining the OData service, check the implementation to ensure that eTag handling is correctly configured for the supported methods. You may need to implement eTag handling for the specific methods if required.
  
  
  Modify Client Logic: If you are using a client application to interact with the OData service, ensure that it is not sending eTags with unsupported HTTP methods. For example, do not include If-Match or If-None-Match headers in requests that do not support eTags.
  
  
  Consult Documentation: Review the SAP Gateway documentation for details on eTag handling and supported HTTP methods for your specific version and configuration.
  
  
  Debugging: If the issue persists, enable debugging or logging in the SAP Gateway to capture more detailed information about the request and response, which can help identify the root cause.
  
  
  Related Information:
  
  eTag: An eTag (entity tag) is a part of HTTP, used for web cache validation and conditional requests from browsers for resources.
  HTTP Methods: Common HTTP methods include GET, POST, PUT, DELETE, PATCH, etc. Each method has specific use cases and behaviors.
  SAP Gateway: SAP Gateway is a technology that allows developers to create OData services that expose SAP data and business logic to external applications.
  
  By following these steps, you should be able to address the /IWFND/CM_MGW537 error and ensure proper handling of eTags in your SAP Gateway services.