How To Fix CL_SADL_GW_MDE_MSG021 - Annotation Target &1 doesn't allow metadata extentions.

SAP Error Message - Details

• Message type: E = Error

• Message class: CL_SADL_GW_MDE_MSG -

• Message number: 021

• Message text: Annotation Target &1 doesn't allow metadata extentions.

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 CL_SADL_GW_MDE_MSG021 - Annotation Target &1 doesn't allow metadata extentions. ?

  The SAP error message CL_SADL_GW_MDE_MSG021 indicates that there is an issue with the metadata extension for an annotation target in the context of SAP Gateway and SADL (SAP ABAP Programming Model for SAP Fiori). Specifically, the error message states that the annotation target specified does not allow metadata extensions.
  Cause:
  This error typically occurs due to one of the following reasons:
  
  
  Incompatible Annotation Target: The annotation target you are trying to extend may not support metadata extensions. This can happen if the target is a standard SAP object that is not designed to be extended.
  
  
  Incorrect Configuration: There may be a misconfiguration in the way the metadata is defined or in the way the extension is being attempted.
  
  
  Missing Annotations: The required annotations for the target might not be present, or the target might not be properly defined in the metadata.
  
  
  Version Issues: There could be compatibility issues with the version of the SAP system you are using, especially if you are trying to use features that are not supported in your current version.
  
  
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Check Annotation Target: Verify that the annotation target you are trying to extend is indeed designed to allow metadata extensions. Consult the SAP documentation or the relevant API reference.
  
  
  Review Metadata Configuration: Ensure that the metadata configuration is correct. Check the definitions and ensure that all required annotations are present.
  
  
  Use Alternative Approaches: If the target does not support extensions, consider using alternative approaches, such as creating a custom entity or using a different target that allows for extensions.
  
  
  Update System: If you suspect that the issue is related to version compatibility, check for any available updates or patches for your SAP system that might resolve the issue.
  
  
  Consult SAP Notes: Look for relevant SAP Notes or Knowledge Base Articles (KBAs) that might address this specific error message. SAP frequently updates its documentation and provides fixes for known issues.
  
  
  Contact SAP Support: If the issue persists and you cannot find a solution, consider reaching out to SAP Support for assistance. Provide them with detailed information about the error, including the context in which it occurs.
  
  
  Related Information:
  
  SAP Gateway: Understand how SAP Gateway works and how it interacts with OData services and metadata.
  SADL: Familiarize yourself with the SAP ABAP Programming Model for Fiori and how it handles annotations and metadata.
  SAP Documentation: Refer to the official SAP Help Portal for detailed documentation on metadata extensions and annotations.
  
  By following these steps, you should be able to identify the cause of the error and implement a suitable solution.