FORZA 5 - does not start - any ideas??

Hi there,
New to this Forza 5 game. I have no problems with installing any of my other games.
Got Forza 5 installed, wanted a 14gb update - did that (waited hours to get to 100%). 100% finally arrived and cannot start. It will not play. Any ideas?

Its a Microsoft issue. Hopefully they will have this issue resolved soon.

Can you not hard restart your console? Hold the power button on the console for 10-seconds and then try and start the game again.