I am not sure how you replaced you inventory data file, but you cannot cut and paste it from another back up. I would restore the last good unaltered backup.

What posting method are you using? Batch? If so, move to Real Time posting. Also, dates matter in this program. Make sure you are posting to the correct date to get the results you are looking for in your reports.   Also look at the report dates.

I do offer remote service and I could look at this with you.  There would be a fee for this service.

Thank you for the reply.
The posting method is Smart Posting. The transaction date entered is correct. The reason I replaced the invcost.dat file is just to see the problem is with this particular file. I know that inventory beginning balance is reside in this file. I tired to unpost all transactions and repost it again. There is no change. I did check that item receipts are entered with values. Hence, any minus adjustment in the inventory adjustment window should compute costs accordingly. There is no chronological order error. The date for receipt is ahead of the date on which inventory adjustment journal is recorded (posted). The problem is that you see the quantity adjustment in the Item cost report but not the value adjusted in the same report from the month of January 2016.

The problem is that you see the quantity adjustment in the Item cost report but not the value adjusted in the same report from the month of January 2016.
Does the item actually have a cost? Sometimes item quantities are entered into inventory with zero cost.

Thank you KIM. The items have cost. There is a purchase recorded with value.

What periods do you currently have open?

The active periods are 2015/15 and 2015/16. The fiscal year year from July 1 to June 30. I rebuilding the company on a test basis with few items. It calculated the cost for the year 2016 as well. What I will going to do is to follow a rebuild process by creating a new company and migrating opening balances and transactions. Thank you for the help.