# 19023: Invalid channel type

Log Type: APPLICATION

Log Level: ERROR

## Description

Twilio returns this error when a request includes an invalid channel type. This usually happens when rich content falls back to a channel that does not support the content type you sent.

### Possible causes

* You are sending rich content and the message falls back to a channel that does not support that content type.
* Your template does not include a fallback content type that matches the destination channel. Twilio uses fallback content types so a single template can deliver rich content to one channel and plain text or media to another.

### Possible solutions

* Add a `twilio/text` fallback when the message can fall back to SMS. Twilio supports `twilio/text` as a fallback content type for mixed-channel messaging.
* Add a `twilio/media` fallback when the message can fall back to MMS. Twilio supports `twilio/media` for MMS and other rich messaging channels.
* When you use Content Templates, include fallback content types for each supported channel before you send the message. Twilio lets you specify fallback content types when rich content is not supported.

#### Additional resources

* [Channel Fallback](/docs/comms/channel-fallback)
* [twilio/text](/docs/content/twilio-text)
* [twilio/media](/docs/content/twilio-media)