Message type: E = Error
Message class:  FKK_ID_XX_ODN - ODN message 
Message number: 056
Message text: Document class &1 assigned to different Amnt-based rule
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The SAP error message FKK_ID_XX_ODN056 indicates that there is a conflict with the document class assigned to a specific amount-based rule in the SAP system. This typically occurs in the context of contract accounts receivable and payable (FI-CA) when the system is trying to process a document that does not align with the expected configuration for that document class.
Cause: The error is usually caused by one of the following reasons: Configuration Mismatch: The document class assigned to the transaction does not match the amount-based rule defined in the system. This can happen if the document class is incorrectly configured or if the amount-based rule is not set up to handle the specific document class. Incorrect Document Class Assignment: The document class may have been assigned incorrectly to a transaction or document type that does not support the amount-based rule. Changes in Configuration: If there have been recent changes to the configuration of document classes
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