# 14300: Start: Invalid nested noun value

Log Type: APPLICATION

Log Level: ERROR

## Description

Twilio returns this error when `<Start>` or `<Stop>` contains a nested noun that does not match the verb's supported TwiML structure. For Voice call recording and real-time transcription, use `<Start><Recording>` or `<Start><Transcription>`, and stop them with matching `<Stop>` instructions when you need to reference them by `name`.

### Possible causes

* You nested a noun under `<Start>` or `<Stop>` that the verb does not support. For Voice, `<Start>` is used with `<Recording>` or `<Transcription>`, and `<Stop>` is used with the matching noun.
* You used `<Stop>` to end a recording or transcription that was never started with a `name`, so Twilio cannot match the stop request to the active session.
* The TwiML is malformed or the noun is not nested directly inside the verb you intended to use. TwiML is an XML instruction set, and nouns must be nested inside the correct verb.

### Possible solutions

* Replace the invalid nested noun with a supported Voice noun. Use `<Start><Recording>` to begin call recording, or `<Start><Transcription>` to start real-time transcription.
* If you need to stop a recording later, give the recording a unique `name` and stop it with `<Stop><Recording name="..."/>`.
* If you need to stop a real-time transcription later, provide a `name` and stop it with `<Stop><Transcription name="..."/>`, or stop it through the Transcriptions subresource API.
* Validate the returned TwiML before you send it to Twilio so every noun is nested under the correct verb.

#### Additional resources

* [Error and Warning Dictionary](/docs/api/errors)
* [TwiML Voice: Recording](/docs/voice/twiml/recording)
* [TwiML Voice: Transcription](/docs/voice/twiml/transcription)