---
page_type: error
code: 80913
message: "80913: Out-Of-Session Callback Error"
level: ERROR
product: Proxy
---

## Description

Callback to Out-of-Session handler returned a non-success status code.

### Possible Causes

- Your Out-of-Session callback URL is invalid.

### Possible Solutions

- Verify that your Out-of-Session callback URL is valid and that your server is correctly processing Out-of-Session callbacks from Proxy.
- Please read over the \[Out-Of-Session Callback guide] (https://www.twilio.com/docs/proxy/out-session-callback-response-guide) for more detailed information.