How do I resolve webhook issues such as “unprocessed events” and 301, 302, 401 or 500 errors?

Troubleshooting webhooks

Webhook event issues can be related to misconfigured webhooks or an issue with cronjob.

Webhooks are responsible for sending the notifications from the Adyen platform to your server. Then, the server sends a notification to the Adobe Commerce integration.

If you’re testing the notification endpoint in Customer Area > Developers > Webhooks > Troubleshoot and the plugin returns with a 301, 302 or 401 error instead of an [accepted] response, there might be something wrong in the webhook endpoint settings.



Webhook response



200 [accepted]

Webhook is working fine

300 errors

Your account’s endpoint isn’t accepting webhooks properly

  • Authentication errors: are the webhook username and password the same in Adobe Commerce and Adyen?
  • If the HMAC key is configured, is it the same in Adobe Commerce and Adyen?
  • Make sure the endpoint URL matches the format in our documentation.

400 errors

The request wasn’t applied. Valid authentication credentials are missing.

  • Authentication errors; are the webhook username and password the same in Adobe Commerce and Adyen?
  • If the HMAC key is configured, is it the same in Adobe Commerce and Adyen?

500 errors

Your server isn’t correctly responding to our backend system.

We can’t perform further action as we have no insight into your server configuration.

The error "Maximum line length limit exceeded" means that the response we receive from the webhook is incorrect. It’s possible it includes [accepted] but it still exceeds the maximum number of characters in the headers or content.

We suggest removing extra headers from the request.

Note: If you’re configuring the endpoint with http, try using https instead.

Note: If you set the SSL version to SSL, try setting it on TLSv1.2 instead.

Issues with webhooks related to cron job

If Adobe Commerce shows the message you have [number] unprocessed notifications when testing the endpoint, there’s a problem with the system's cron job. The Adobe Commerce cron doesn’t only accept the webhooks, but also has to process the webhooks to update the status in Adobe Commerce.

Sometimes the issue is related to your server communication and cron. In that case, the comment history on your order page wouldn't show the Adyen HTTP Notification(s) messages.

To process payments, the Adobe Commerce cron will have to acknowledge each of the webhook events we send to your server with an [accepted]. Second, your cron will need to process the webhook events.

Tip: Find more possible reasons you don’t receive webhook events.



Processing notifications

If the notifications are being accepted, it's possible the cron isn't processing the notifications. Check this by testing the configuration in the Webhooks (with the Edit & Test button).

Note: In those cases, please check your cron.

Tip: If this didn’t help, contact our support and attach the order page screenshot and log files.


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