---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/31426#article
headline: "31426: Upgrade Required"
url: https://www.twilio.com/docs/api/errors/31426
inLanguage: en
dateModified: 2025-12-12T18:14:22.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 31426: Upgrade Required

Log Level: ERROR

## Description

This error is raised when an HTTP 426 response is received. The reason for this is most likely because of an incompatible TLS version. To mitigate this, you may need to upgrade the OS or download a more recent version of the SDK.