DTW : Change UOM in AR Invoice

Hi,

I have question on import DTW, I have set UOM group in Item : 1 Box = 50 pcs

and I try to import AR invoice by using DTW and use field UoMEntry to specific uom as 31 or 2 (which is UoMEntry in table OUOM) but system show error, "Internal error (-10) occurred Internal error (-10) occurred65171"

is there any solution for this.

Moreover is there any solution for import AR Invoice with gross mode and discount?