---
title: underlyingErrorsKey
framework: ClassKit
role: symbol
role_heading: Type Property
platforms: [iOS 11.3+, iPadOS 11.3+, Mac Catalyst 11.3+, macOS 11.0+, visionOS 1.0+]
path: classkit/clserroruserinfokey/underlyingerrorskey
---

# underlyingErrorsKey

A key whose value is the array of errors that contributed to this error.

## Declaration

```swift
static let underlyingErrorsKey: CLSErrorUserInfoKey
```

## Discussion

Discussion This key only appears for errors with code partialFailure in Swift or CLSError.Code.partialFailure in Objective-C, signifying that more than one error occurred.

## See Also

### Keys

- [objectKey](classkit/clserroruserinfokey/objectkey.md)
- [successfulObjectsKey](classkit/clserroruserinfokey/successfulobjectskey.md)