Message type: E = Error
Message class:  UXS - Messages Package UXS 
Message number: 204
Message text: Internal error: Key of an XML proxy object is incomplete
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The SAP error message UXS204, which states "Internal error: Key of an XML proxy object is incomplete," typically occurs in the context of SAP's XML-based services, particularly when dealing with proxy objects in SAP PI/PO (Process Integration/Process Orchestration) or when using web services.
Cause: The error usually arises due to one of the following reasons: Incomplete Key Definition: The key fields required for the XML proxy object are not fully defined or are missing. This can happen if the data being processed does not include all the necessary identifiers that the system expects. Mapping Issues: If there is a problem in the mapping of the XML data to the corresponding structure in SAP, it can lead to incomplete keys being passed to the proxy object. Configuration Errors: Incorrect configuration in the service interface or the proxy settings can lead to this error. This includes issues in the service definition or the way the proxy is
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