While creating Supplier invoice you would get this error .
SAP Business ByDesign
Since these fields are used to determine the financial postings details like GL account, so one of them is mandatory.
So as per the error message, you must enter one of the fields
tax code not determined purely based on supplier master data, why does the system ask for Product Id or category or GL account , KBA , SRD-SRM-SI , Supplier Invoicing , Problem