Sage 300

Our client is working on Sage 300 2014 PU3. When doing the Physical Inventory Reconciliation it gave an error that states "There is insufficient quantity available to adjust item XXX at location XXX". When checking the specific item via Item Location…

I have a couple of items with negative average cost. What's the best way to fix this in Sage 300 5.5? TIA, Peter Heinicke