Once the year is closed, corrections to that year may still be made. If corrections are necessary, it is highly recommended that any financial statements that were printed from the period where the correction was made forward be reprinted after the correction has been made to assure that all financial statements correctly reflect the activity as corrected.
The accounting year/accounting periods must still exist in order to make corrections in a closed year. If the accounting year/accounting periods have been deleted, then corrections within those years/periods is not possible.