---
title: "failedToActivateDevice(_:session:error:)"
framework: mediadevice
role: symbol
role_heading: Instance Method
path: "mediadevice/mediadeviceroutingmanager/failedtoactivatedevice(_:session:error:)"
---

# failedToActivateDevice(_:session:error:)

Reports a device activation failure to the system so it can inform the user and clean up the session.

## Declaration

```swift
@MainActor final func failedToActivateDevice(_ device: MediaOutputDevice, session: MediaOutputSession, error: MediaDeviceError)
```

## Parameters

- `device`: The device that activation failed for.
- `session`: The session associated with the activation.
- `error`: The error that occurred during activation.

## Mentioned in

Creating a media device extension

## Discussion

Discussion Call this function when activation has failed for a device.