Message type: E = Error
Message class:  EDOCUMENT_IN - Messages for eDocument India 
Message number: 036
Message text: Invoice Date of Reference Invoice & is initial
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The SAP error message EDOCUMENT_IN036 indicates that the invoice date of a reference invoice is initial (i.e., it has not been set or is blank). This error typically occurs in the context of electronic invoicing or document processing within SAP, particularly when dealing with invoice documents that reference other invoices.
Cause: Missing Invoice Date: The reference invoice that is being used does not have a valid invoice date set. This could happen if the invoice was created without specifying a date or if there was an error during the invoice creation process. Data Entry Error: There may have been a mistake during data entry, leading to the omission of the invoice date. System Configuration: There could be issues with the configuration of the electronic document processing system, which may not be correctly handling the reference invoice data.
Solution: Check Reference Invoice: Go to the reference invoice in the SAP system and verify if the invoice date
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