...
// Delete the following line.
  GLSetup.GetRoundingParamenters(Currency,RoundingPrecision,RoundingDirection);
  Currency.TESTFIELD("Invoice Rounding Precision");
  InvoiceRoundingAmount :=
    -ROUND(
      TotalSalesLine."Amount Including VAT" -
      ROUND(
        TotalSalesLine."Amount Including VAT",
        Currency."Invoice Rounding Precision",
        Currency.InvoiceRoundingDirection),
// Delete the following line.            
      RoundingPrecision);
  IF InvoiceRoundingAmount <>0 THEN BEGIN
    CustPostingGr.GET(SalesHeader."Customer Posting Group");
    CustPostingGr.TESTFIELD("Invoice Rounding Account");
    WITH SalesLine DO BEGIN    
...
...
  Currency.TESTFIELD("Invoice Rounding Precision");
  InvoiceRoundingAmount :=
    -ROUND(
      TotalSalesLine."Amount Including VAT" -
      ROUND(
        TotalSalesLine."Amount Including VAT",
        Currency."Invoice Rounding Precision",
        Currency.InvoiceRoundingDirection),
// Add the following line.           
      Currency."Amount Rounding Precision");
  IF InvoiceRoundingAmount <> 0 THEN BEGIN
    CustPostingGr.GET(SalesHeader."Customer Posting Group");
    CustPostingGr.TESTFIELD("Invoice Rounding Account");
// Add the following lines.        
    IF GLSetup."Rounding VAT (LCY)" <> GLSetup."Amount Rounding Precision" THEN BEGIN
      GLAcc.GET(CustPostingGr."Invoice Rounding Account");
      IF VATPostingSetup.GET(SalesHeader."VAT Bus. Posting Group",GLAcc."VAT Prod. Posting Group") THEN
        IF VATPostingSetup."VAT %" <> 0 THEN
          ERROR(Text054,CustPostingGr.FIELDCAPTION("Invoice Rounding Account"),CustPostingGr."Invoice Rounding Account");
    END;
// End of the added lines. 
        
    WITH SalesLine DO BEGIN
...
...
   ELSE
    VALIDATE(
      "Unit Price",
      ROUND(
        InvoiceRoundingAmount /
        (1 + (1 - SalesHeader."VAT Base Discount %" / 100) * "VAT %" / 100),
// Delete the following line.                
        RoundingPrecision));
  VALIDATE("Amount Including VAT",InvoiceRoundingAmount);  
...
...
  ELSE
    VALIDATE(
      "Unit Price",
      ROUND(
        InvoiceRoundingAmount /
        (1 + (1 - SalesHeader."VAT Base Discount %" / 100) * "VAT %" / 100),
// Add the following line.                
        Currency."Amount Rounding Precision"));
  VALIDATE("Amount Including VAT",InvoiceRoundingAmount);  
...