I just bought an xbox one and Halo 5. It took all but 2 hours yesterday to update the xbox and now Halo has been on 0% for 3 hours after installing. Any one got any ideas?
You can try doing an Xbox Hard reset which is holding the Xbox power button for 10 seconds, that worked for me.
If not you might need to try longer solutions from here: http://support.xbox.com/en-US/games/troubleshooting/game-installation-process-stops
Hope your problem gets solved and welcome to the Xbox community!
Are you on ethernet? It has had pretty large updates.