Symptom:
The error message "Payment failed" shows up in the checkout.


Solutions:
First, check all settings in the payment provider backoffice and in Magento according to the documentation. Many times, this is just a configuration error somewhere.


If the issue persists, please take a closer look at these points:

  • Are you using the most recent version of the module? If not, please update it.
  • Is the API-user configured according to the documentation? Username and password must be identical in Magento and the payment provider backoffice.
  • Is Alias Gateway enabled? Check this in the payment provider backoffice in "Configuration -> Account -> Your options". Alias Gateway is called "OPC" (One Page Checkout) there.
  • Are the Feedback-URLs in the payment provider backoffice correct and working? See this article on how to check.
  • Are the gateway-URLs in Magento filled in and correct? Note the difference between test and prod URLs.
  • Are SHA-IN and SHA-OUT and the hash-algorythm configured according to the documentation? These must be identical in Magento and the payment provider backoffice.
  • Check the logfile "/var/log/ops.log" and the error messages in the payment provider backoffice for more detailled error-messages.
  • Check the webserver logs (Apache, nginx, etc.) and the Magento logs for errors that occur when the payment is attempted.


Further hints:

If the above didn't resolve the problem please check if it caused by one of the following issues: