Message type: E = Error
Message class:  FDM_INVHISTORY - Messages for Invoice History 
Message number: 021
Message text: Document has not been posted yet; document display not possible
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The SAP error message FDM_INVHISTORY021 indicates that the document you are trying to display has not yet been posted in the system. This typically occurs in the context of financial document management or inventory management, where users may attempt to view a document that is still in a draft or unposted state.
Cause: Unposted Document: The most common cause is that the document (such as an invoice or journal entry) has been created but not yet posted to the general ledger or relevant accounting module. Incomplete Transactions: The transaction may be incomplete, meaning that all required fields or steps have not been fulfilled. User Permissions: In some cases, the user may not have the necessary permissions to view unposted documents.
Solution: Post the Document: If you have the necessary permissions, you can navigate to the relevant transaction (e.g., MIRO for invoices, FB50 for journal entries) and post the document. Ensure that all required fields are filled
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