---
page_type: error
code: 12100
message: "12100: Document parse failure"
level: ERROR
---

## Error - 12100

### Document parse failure

Twilio was unable to parse the provided XML Document.

Your TwiML document must be a valid XML Document, or Twilio will not be able to read your document. You can debug XML parsing errors by getting the response body in the [debugger](/user/account/debugger), and then using an online validation tool like the [W3C Validation Service](http://validator.w3.org/#validate_by_input).

#### Possible Causes

- There is a leading space, or an empty line, before the XML type header (i.e. `<?xml version="1.0" encoding="UTF-8"?>`)
- The root `<Response>` element is missing
- There is an unclosed element
- There is an unquoted attribute
- There is an improperly nested element

#### Possible Solutions

- Make sure there is no extra space or line at the beginning of the file before the type header
- Make sure your root element is \<Response>
- XML is case sensitive, make sure your start and end elements match case. (Twilio elements begin with a capital letter)
- Make sure characters such as < > and & are escaped properly, as `&lt; &gt; and &amp;`.