Netflix says 'Play on device failed - Failed to detect device.'

1. Hold the button on the Chromecast for 25 seconds, or until the indicator light begins flashing.

   Note:Resetting your Chromecast will erase any settings previously saved on the device. Follow Google's steps to reconfigure your Chromecast.

2. Once you have reset the device, reconnect it to your Netflix account.

If you continue to experience this error after performing a full factory reset, there may be an unrecoverable issue with your device. Reach out to your device manufacturer for more assistance.