Message type: E = Error
Message class:  FKK_ID_XX_ODN - ODN message 
Message number: 054
Message text: Unknown doc.class &1 was set in the customer-specific class &2
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The SAP error message FKK_ID_XX_ODN054 indicates that there is an issue with a document class that is not recognized in the context of a customer-specific class. This typically occurs in the SAP Convergent Charging (SAP CC) or SAP Contract Accounts Receivable and Payable (SAP FI-CA) modules, where document classes are used to categorize and manage financial documents.
Cause: Unknown Document Class: The document class specified in the transaction or configuration does not exist in the system. This could be due to a typo, a missing configuration, or an incorrect assignment. Custom Configuration: The error may arise from a custom implementation where the document class was defined but not properly registered or activated in the system. Transport Issues: If the system has recently undergone a transport of changes, the document class may not have been included or properly transported.
Solution: Check Document Class: Verify that the document class specified in the error message is correctly defined in
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