---
page_type: error
code: 11206
message: "11206: HTTP protocol violation"
level: ERROR
product: Programmable Messaging
---

## Description

There was an error speaking HTTP to the target URL.

### Possible Causes

- Server misconfiguration
- Network disruption
- Making HTTP connections to an HTTPS port
- There is an invalid symbol in the TwiML Cookie

### Possible Solutions

- Verify your web server is serving valid HTTP for the URL
- Verify the network connection to your server is stable
- Verify the URL is not directing you to an SSL port
- Remove the following characters from the TwiML Cookies: '\t', '\r', '\n', '\v', '\f'
- TwiML cookies cannot have an empty name