Aging or Ledger balance is not the same as the General Ledger Trial Balance
Typically this is due to data entry errors.
To find the errors, run the the sub-ledger report (Accounts Payables / Reports / AP Ledger) or aging report (Accounts Payables / Reports / Vendor Aging) and the General Ledger report (General Ledger / Reports / General Ledger) side by side until the month in which they balanced is located.
Then start with the first month they are off, print the two reports and reconcile them side by side. Once the discrepancy is located, an adjustment can be made.
Some common data entry errors:
1. Look at GL sub-ledger account in detail see if the transaction date and GL posting are in the same period.
2. A transaction was paid prior to the transaction date or payment was received prior to invoice / bill date.