Press the Xbox home button on your controller. (If you game is frozen and the home menu will not come up, please skip ahead to Power Cycle your console.)
Press the Menu button on your controller and select Quit to exit the game currently running.
Try to Restart the game.
Power Cycle Your Console
Fully shut down your console by holding both the Xbox button on the face of your console for 10 seconds.
Reboot your Xbox by either reconnecting your controller or pressing the Xbox button on the face of your console.
Try to Restart the game.
Test your Connection
Press the Xbox button to open the Guide
Select Profile and Systems > Settings > General > Network Settings. Any outages will appear on your Network Status displayed here.
In the Network Settings window you will want to select the Test Network Connection option. If the test succeeds your Xbox will be properly connected to your network.
If this is not successful select the Troubleshoot Your Xbox Network Connection option.