Changing the UNIT cost of an item

Hi everyone,
I have an item with a wrong unit cost(the correct value is zero but it is not).
I have already run the batch Adjust Cost - Item Entries but it didn’t got me any result.
I tried the revaluation journal with my item but I got the following error message:

You must not revalue items with Costing Method Average, if Calculate Per is Item Ledger Entry.

What shall I do?
Thanks in advance :mrgreen:

If costing method is average then you can not do revaluation of Item.

So, what to do ??

And how did you find the cost is zero ?