Nominal codes can close after a set period, it is then possible to filter so these nominal codes do not appear on the Nominal code list.
To view all Nominal codes:
Click Nominal Ledger, Nominal Accounts.
Click the filter icon.
Check the Must be open in year option is clear.
Click Apply.
See if the accounts show then. Once the account is found, to change the Closed After Period dates on the Nominal account:
Click Nominal Ledger, Nominal Accounts.
Locate and select the required nominal account.
On the Attributes tab, change or remove the Closed After Period.