Message type: E = Error
Message class:  FMCCAVC - Message class CCAVC - Cash control 
Message number: 131
Message text: Source ledger &1 already used, try another
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The SAP error message FMCCAVC131 indicates that the source ledger specified in your transaction is already in use, and you need to select a different source ledger. This error typically occurs in the context of Financial Management (FM) or Controlling (CO) modules when trying to post or process financial documents.
Cause: Ledger Already in Use: The specified source ledger is already being utilized in another transaction or document, which prevents it from being used again in the current context.
Configuration Issues: There may be configuration settings in the system that restrict the use of certain ledgers under specific conditions. Concurrency Issues: If multiple users are trying to access or post to the same ledger simultaneously, it can lead to this error.
Solution: Select a Different Ledger: The simplest solution is to choose a different source ledger that is not currently in use. Check for Open Transactions: Investigate if there are any open transactions or documents that are
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