This error occurs when a stock item you are trying to invoice has a negative cost. MYOB does not allow sale of items with negative cost therefore update the item and change the cost. Once changed you can import invoices that include this item.
The sale is not importing successfully as the item has a total value of (-0.01). So MYOB will not allow this item to be sold as it cannot allocate a negative average cost to the sale.
The reason as to why this occurs is due to the rounding MYOB must perform when multi-currencies are used or multi-line transactions are inserted. To minimise this from occurring, as the MYOB software will start the rounding process from the bottom line and work upwards, it is therefore recommended to purchase the items where the lines with nil values are listed first.
You may also want to implement a check that all inventory totals have a non-negative value on hand. If they are not, then an inventory adjustment will need to be entered to bring the total value to nil or higher.