Urgent help - Purchase packing slip error

Hi All,

When I was creating salesorder -> purchase order from the salesorder -> posting packing slip,

it was trying to post the salesorder packing slip and so I am getting the error since the inventory physical is in -1. I don't know why it is calling Sales packing slip while posting PO packing slip...

But when I was creating a Direct PO , no problem is happening .. Any help will be appreciated..

Thanks and regards,

Enrique