Hi Everybody,
We have done a inventory closing on 2018-05-31 but later discovered that some on hand items have a too low cost price.
We want to change this to the correct cost price but it doesn't work. See detailed description below.
In the Inventory management we go to "Closing and adjustment".
We select the closing and go to "Adjustment / on hand"

In the next form I find the (weighted average) product I want to adjust the cost price of by using the Select menu.
My product is then showed.
I got 85 on-hand and the cost price is 0,20. The real cost price should be 15,34 and I enter this in the form.

Then i click "Post".
In the adjustment of on-hand inventory I select "Item number".

When clicking ok I get the message that "Fiscal period for 2018-05-31 is not open."

I don't understand this message.
The inventory is closed, yes I know but why is there menu choice indicating that the value of the on-hand could be changed?
Am I doing something wrong?
If I should not use this function, how could I change the cost price of on-hand items?