How To Fix /IWFND/CM_MGW_RT022 - GW internal error. Empty SCHEMA must not happen.

SAP Error Message - Details

• Message type: E = Error

• Message class: /IWFND/CM_MGW_RT -

• Message number: 022

• Message text: GW internal error. Empty SCHEMA must not happen.

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message /IWFND/CM_MGW_RT022 - GW internal error. Empty SCHEMA must not happen. ?

  The SAP error message /IWFND/CM_MGW_RT022 GW internal error. Empty SCHEMA must not happen typically occurs in the context of SAP Gateway services, particularly when there is an issue with the metadata or the service definition. This error indicates that the system encountered an empty schema when it was expecting a valid schema definition, which is crucial for the proper functioning of OData services.
  Causes:
  
  Missing or Incorrect Metadata: The service might not have a properly defined metadata structure, leading to an empty schema.
  Service Registration Issues: The OData service may not be correctly registered or activated in the SAP Gateway.
  Model Issues: There could be issues with the data model or entity types defined in the service.
  Backend Issues: Problems in the backend system (like missing data or incorrect configurations) can also lead to this error.
  Transport Issues: If the service was transported from one system to another, there might be inconsistencies in the transport.
  
  Solutions:
  
  
  Check Service Metadata:
  
  Go to the SAP Gateway Client (transaction /IWFND/GW_CLIENT) and check the metadata of the service. Ensure that the schema is correctly defined and not empty.
  You can also check the service using the URL: http://<host>:<port>/sap/opu/odata/sap/<service_name>/$metadata.
  
  
  
  Re-register the Service:
  
  Use transaction /IWFND/MAINT_SERVICE to check if the service is properly registered. If not, register it again.
  Ensure that the service is activated.
  
  
  
  Check Data Model:
  
  Review the data model and entity types in the service definition. Ensure that all necessary fields and types are defined correctly.
  
  
  
  Debugging:
  
  If you have access to the backend, you can debug the service to see where the empty schema is being generated. Look for any exceptions or errors in the code that might lead to this issue.
  
  
  
  Check Backend System:
  
  Ensure that the backend system is functioning correctly and that all necessary data is available. Check for any inconsistencies or missing configurations.
  
  
  
  Transport Consistency:
  
  If the service was transported, ensure that all related objects (like data models, service definitions, etc.) were transported correctly and are consistent in the target system.
  
  
  
  Check for Notes and Patches:
  
  Sometimes, this error can be related to known issues in specific SAP versions. Check the SAP Support Portal for any relevant notes or patches that might address this issue.
  
  
  
  Related Information:
  
  SAP Notes: Search for relevant SAP Notes in the SAP Support Portal that might provide additional insights or fixes for this error.
  SAP Community: Engage with the SAP Community forums to see if other users have encountered similar issues and what solutions they found effective.
  Documentation: Review the official SAP documentation for OData services and SAP Gateway for best practices and troubleshooting steps.
  
  By following these steps, you should be able to identify the root cause of the error and implement a solution to resolve it.