Message type: E = Error
Message class:  CL_SADL_GW_MDE_MSGX - texts for parser 
Message number: 030
Message text: Entity & does not allow metadata extensions
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The SAP error message CL_SADL_GW_MDE_MSGX030 typically indicates that you are trying to extend the metadata of an entity that does not support extensions in the SAP Gateway framework. This can occur in scenarios where you are working with OData services and attempting to add custom fields or properties to an existing entity that is not designed to allow such modifications.
Cause: Entity Restrictions: The entity you are trying to extend may be defined in a way that does not allow for metadata extensions. This is often the case with standard SAP entities that are not designed for customization. Service Configuration: The OData service may not be configured to allow extensions. This can happen if the service is not set up to support custom fields or if the underlying data model does not permit changes. Technical Limitations: Some entities are inherently limited by their design in the SAP system, meaning they cannot be extended due
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