This message appears when you try to edit or delete a transaction that was posted automatically, for example, transactions created via the Write Off, Refunds and Returns Wizard. This is because the reference on this type of transaction indicates that it was generated automatically.

Don't worry, if you amend the transaction reference you can then edit or delete the transaction. Let's take a look. 

1. Click Transactions, then select the transaction you want to edit or delete, then click Edit.
2. In the Reference field, delete the existing reference, click Save then click Yes.

That's it. You can now go ahead and edit or delete the transaction as required.