MR21 - Error in price change

Hi,

When we try to make a price change for a configurable material against the sales order and its line item in MR21, we are getting the following error message

"Valuation data for material xxxx for sales order xxxxx 00010 does not exist - message no. MM124"

Could you please let me know how to resolve this issue.

Thanks & Regards,

Dwarak.