Error during conversion to alternative unit of meas

Hi All,

When I create material, Base unit is M, Order unit is M2, issue unit is Role.

In Additional data \ Units of measure, I add M -> M2 and M -> Role

In Additional data \ Proportion/prod.unit, I chose Units meas. use B and actual M per Role.

When I create PO and Goods receipt have a error message " Error during conversion to alternative unit of meas. M: correct qty Correct qty xxxxxxx M2"

Message no. XU058

Pls help me resolve it.

Ngocvt.