Issue in Transacting Move Orders.

Hi,

I have got a move order line having qty 20.
Now primary qty for that line is showing as 20 and qty delivered is showing as 19.

The line is apperaring in transact move order form with
transaction qty =1, Requested qty=20,Deliver Qty=19,Allocated Qty=20;

Allocate button is Greyed out.
When trying to view allocation: Allocation qty is showing as null for this line.
Available is 1 and on hand is 1.

I am not able to trasact this line now.

Can anyone please advise how to proceed?

Thanks.