I am getting an error while try to place order using Sagepay payment method. When I click Order Place button, an alert message is showing. Like:

Can't load serializer adapter "Phpserialize".

enter image description here

2 Answers 2


This is a problem for older Sage Pay Suite Pro versions. On 4.2.16 and forward you should not experience this problem anymore.

Kind Regards, Santiago.


Please check your SagePay plugin version. I had the same issue right after the upgrade to Magento I contacted ebizmarts.com and they said this issue was fixed in the latest release of their plugin sage-pay-suite-pro-4.2.16. Please try updating, in our case, it fixed the problem and also helped resolving the issue which slow loading checkout page.

You can experience the same issue in Mailchimp plugin which also have been resolved in the latest release of their plugin.

  • Pludin updated. order placed from laptop but not from mobile. Feb 19, 2020 at 14:19
  • I don't see a reason why this would not work on mobile. Please clean cache and re-test. Problem was related to something that is happening on the server-side not the client. Feb 20, 2020 at 13:47
  • I tested again. order placed but success page not showing. Showing 404 Feb 20, 2020 at 14:43
  • 404 would suggest page not found. Please inspect your redirect url after payment if pointing to correct place. Feb 21, 2020 at 16:48

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.