You can identify and access a transaction from an invoice, a report, or a contact activity list. However, you can not delete the transaction from within the transaction window, and you need to be on the banking activity list to be able to delete the transaction.
TIP: Please note the transaction's date to reference it as you access the banking tab.
If you receive an error message, this may be due to various reasons:
If the reconciliation process has not been completed, you can remove the reconciled status. Refer to How to remove the reconciled status of a transaction