Sage 100

Dear concern, I am using sage erp 100. I accidentally deleted batch . Now can not post invoices. But these invoices hold items which are not available for sale. I want to cancel or delete these invoices. Please help me to solve this problem

Unit price drops down to 0 when changing the quantity of "ordered" on the same line item. Is this normal behavior, or was this intentionally implemented at some point? Can anyone point me in the direction of an article to reverse this? Thanks!