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# AccessoryTransportSession.Error

Errors that can occur with an accessory transport session.

```
enum Error
```

## Topics

### Identifying session errors

[`AccessoryTransportSession.Error.invalidated`](/documentation/AccessoryTransportExtension/AccessoryTransportSession/Error/invalidated)

An error that indicates the session is invalidated.

[`AccessoryTransportSession.Error.unsupported`](/documentation/AccessoryTransportExtension/AccessoryTransportSession/Error/unsupported)

An error that indicates the framework doesn’t support an client-provided value or operation.

[`AccessoryTransportSession.Error.unknown`](/documentation/AccessoryTransportExtension/AccessoryTransportSession/Error/unknown)

An error that indicates a failure with an unknown cause.

### Describing an error

[`description`](/documentation/AccessoryTransportExtension/AccessoryTransportSession/Error/description)

A string that describes the transport-session error.


---

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