Unit of Measure Error on Expense PO

Hi,

We are getting an issue of UOM error (JDE WS A7.3 cume 12) when  doing a voucher match thru P4314  on  open Expense PO line (Line Type J and Purchase Order lines has UOM as each EA and CA 'case' for line types J).Not sure where the UOM defaulted and why is the UOM error when voucher matching  expense line of PO.

Any suggestions what needs to be done to get rid of this error. We simply need to close /cancel this  open line (we tried option 7 and option 9 to close /cancel this line but same UOM error.)

Thanks,