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# parser(_:validationErrorOccurred:)

Sent by a parser object to its delegate when it encounters a fatal validation error. `NSXMLParser` currently does not invoke this method and does not perform validation.

```
optional func parser(_ parser: XMLParser, validationErrorOccurred validationError: any Error)
```

## Parameters

`parser`

A parser object.

`validationError`

An [`NSError`](/documentation/Foundation/NSError) object describing the validation error that occurred.

## Discussion

---

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