"Failed to save record because This transaction has duplicate accounts. The main line of the transaction and the line labeled '' both use the account named 'Checking - WF'."
With the above error, this means that some of the customer deposits/cash sales/refunds are already under 'Checking - WF' Account (see NS Account to confirm).
To fix the error, you will need to make sure all charges and refunds for your payout are in Undeposited Funds so when the Payout flow runs, it will create a Deposit and add all from UndepFunds to the Main Checking - WF Account.
This does not apply to Checking WF only but also to other accounts. Any transaction in other accounts instead of Undeposited Funds will result to an error.