Quote Originally Posted by uyutom View Post
Install cod payment, jump normally. If i change to third-party payment, it is not alright, can I send you the error? thank you
I received the OPC log and can confirm that the payment method that you are using is not compatible with OPC. It adds information to the customer's session during the transition from the data-collection to the confirmation step of the checkout.

You can try adding your custom payment method to the list of payment modules that require confirmation (see the OPC plugin's configuration settings).