No worries - under the Edit menu you should find 'Account History'. You will be able to see balances and net changes for a previous year.

If you posted your Year End Adjustments using the Adagio Ledger 90A feature to the 'year end adjustment' period, you also need to click the 'year end adjustment' toolbar button in the financial reporter in order to include them. This is the button with 'YE' and a green check mark. If you don't see this button, you should reset your toolbar from the View / Customize function within the financial reporter.

And as for the formula, what is the field code used for reporting the closing and opening amounts? This could be important. OPEN or BAL_Y for the current year opening? BAL or CURBAL or BAL_[12]M or another for the previous year closing?