Message type: E = Error
Message class:  FAGL_POST_SERVICE - Messages for Package FAGL_POSTING_SERVICES 
Message number: 016
Message text: Leading ledger does not require its own document number
In the leading ledger, the document number of the entry view (BELNR) ist
always taken as the document number (DOCNR).
The system issues an error message and will not allow you to continue with this transaction until the error is resolved.
You only have to perform this function for specific ledgers:
This function is <ZH>not </>required for the leading ledger.
You must perform this function for any ledger that has a different
fiscal year variant to that of the leading ledger.
Performing this function is optional for all other ledgers.
Error message extract from SAP system. Copyright SAP SE.
The SAP error message FAGL_POST_SERVICE016, which states "Leading ledger does not require its own document number," typically occurs in the context of posting financial documents in the General Ledger (G/L) accounting module. This error is related to the configuration of the leading ledger in your SAP system.
Cause: Configuration Issue: The leading ledger in your SAP system is configured in such a way that it does not require a separate document number for postings. This is often the case when the system is set up to use a single document number across all ledgers. Document Number Range: The document number range for the leading ledger may not be set up correctly, or the system is trying to generate a document number that is not required. Posting Logic: The posting logic may be attempting to create a document number for the leading ledger when it is not necessary, leading to this error.
Solution: Check Ledger Configuration: Review
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