SAP Message W/026 - Material &: Purchasing unit & cannot be converted to sales unit

Diagnosis
The quantity in the order price unit could not be converted into aquantity in the sales unit. Therefore values related to the purchaseprice and sales quantity (remaining values) could not be determined.

System Response
The corresponding fields remain empty.

Procedure
Enter a conversion factor for the units of measure so that the systemcan determine the values in question.