Multi-Location Inventory Feature : Inventory Valuation Report shows zero Average Cost and Last Purchase Price for all locations, Item record shows values for these.

When Multi- Location Iventory (MLI) is on, Average Cost is displayed only for the item's preferred location. If there is no preferred location defined for an item, the average cost and last purchase price displayed on the report is blank or zero.

Alternate Solution: Enter a preferred location on the item records.

NOTE : The ability to show average cost and last purchase price for all locations even without setting preferred location on items is currently covered by Enhancement (Issue 156866).