Skip to main content
Question

Blank error but despite successful Test Send Request

  • November 25, 2025
  • 3 replies
  • 18 views
A
Contributor I
Forum|alt.badge.img

Hi there! I was trying to set up SMS webhook integration in Klaviyo Flows. While I got the flows working, the Test Send Request sends out a blank error - the weird part is that the Test goes out successfully even with the error. See screenshot:

This seems to come up inconsistently - after a few Send Test Requests, it sends out Successfully sent webhook response and then in the next Test Send Request this comes up again. Note that the test send request fires the SMS successfully even with the blank red error banner.

Could anyone tell me what could this possibly mean? Thank you so much in advance!

3 replies

whereisjad
Expert Problem Solver IV
Forum|alt.badge.img+16
  • whereisjad
  • Expert Problem Solver IV
  • November 25, 2025

​@Angiekinsss hard for us to tell what is going on if we don’t know the method called and what the HTTP Response from it is.  Could it be that despite the SMS sending successfully it is not a 2xx HTTP code response?

— Jad A | Klaviyo + Shopify + API Integrations Specialist • 7+ Years' Experience Helping with new setups, seamless integrations, and API connections—happy to connect. https://jad-klaviyo-solutions.vercel.app/
A
Contributor I
Forum|alt.badge.img
  • Angiekinsss
  • Author
  • Contributor I
  • November 27, 2025

​@Angiekinsss hard for us to tell what is going on if we don’t know the method called and what the HTTP Response from it is.  Could it be that despite the SMS sending successfully it is not a 2xx HTTP code response?

Thanks for checking in! The HTTP Response, when I tested thru Postman, shows 200 OK in a successful test. I assume it would be the same with Klaviyo webhooks as the same URL is used for both Postman and Klaviyo webhooks. Method is in POST.

Byrne C
Community Manager
Forum|alt.badge.img+27
  • Byrne C
  • Community Manager
  • December 1, 2025

Hi ​@Angiekinsss,

Can you confirm that even when you receive the red error banner near the top of your screen, the webhook sends as expected and you achieve the result you were looking to achieve? Looks like you want an SMS message to send when this webhook sends, correct?

If so, then I’d say that it’s very likely this is a temporary UI error, rather than an error with the webhook actually not sending.

Terms & ConditionsAccessibility statement

Links & Resources

Platforms

Partners

Useful Things

About

  • Terms and Privacy |
    © 2024 Klaviyo All rights reserved. Klaviyo and the Klaviyo logo are trademarks or registered trademarks of Klaviyo, Inc. or its affiliates.