Skip to content Skip to navigation Skip to topbar

Twilio Docs

Error and Warning Dictionary Debugging Your Twilio Application Alarms

Messaging
Voice
Serverless
Flex
Studio
All docs...

SDKs
Help

Log in
Sign up

Rate this page:

12345

On this page

ERROR: 21406
Error - 21406

Cannot set SmsFallbackUrl without setting SmsUrl

Cannot set SmsFallbackUrl without setting SmsUrl

Cannot set SmsFallbackUrl without setting SmsUrl

ERROR: 21406

ERROR

Error - 21406

Cannot set SmsFallbackUrl without setting SmsUrl

You cannot set a fallback URL without specifying a primary URL

Rate this page:

12345

Need some help?

We all do sometimes; code is hard. Get help now from our support team, or lean on the wisdom of the crowd by visiting Twilio's Stack Overflow Collective or browsing the Twilio tag on Stack Overflow.

Terms of service

Copyright © 2024 Twilio Inc.