In a cutscene doing legendary mission, game just stuttered and locked up. Watched it for a few minutes and it acted like it wanted to unfreeze. Stuttered a couple times and then stayed stuck. This happens quite often. Usually in the middle of actual gameplay.
Try these steps:
You can also try clearing your MAC Address and doing a hard reset on your Console.
Go to Settings, Network, Advanced Settings, Alternate MAC Address, and Clear. Then fully turn off your Console for 30 seconds or so, and turn it back on.
If you'd like, you can also try Uninstalling/Reinstalling Anthem.
Let us know if this helps.