The Xbox One SmartGlass app becomes disconnected while you're playing a game, and then you're unable to reconnect to the console.

To resolve this issue:

1. Press the Xbox button to open the guide.
2. Select Settings.
3. Select All settings.
4. Select Power & startup.
5. On the Power & startup screen, select the Power mode setting.
6. Change the power mode to Energy-saving.
7. Restart your console by following these steps:
   1. Press the Xbox button to open the guide.
   2. Select Settings.
   3. Select Restart console.
   4. Select Yes to confirm.
   
   Note If you're unable to access the guide or if the console appears to be frozen, press and hold the Xbox button on the console for 10 seconds, until the console turns off. After the console shuts down, touch the Xbox button on the console again to restart.

Once your console restarts, try to start the application again.