This error sounds like the duplicate key when the same account name is in the Chart of Accounts twice.Run Test & Correct Files | Account Alphabetical Index. A message should appear stating two account with the same name. From the Accounts menu, select Change or Delete Account Names. Enter one of the account numbers (or enter the name and the list will popup and then select one of the duplicate account names). Change the name to something different. Now try going to the Chart of Accounts.