This article outlines the steps to find and fix a Trial Balance and Balance Sheet that are out of balance. The most common cause is transactions that cross months. All dates, on agent check records, need to be in the same month as the Payment Received date on the Details tab of the sale. Once you fix the dates in the sales, you will be in balance.
Navigate to GL>>Processing>>Post the General Ledger, select the correct Ending Date and select the Show Exceptions button.