Spartans! There is currently an issue with the pre-orders of Halo 5: Guardians on the Xbox One that may affect a small number of people who pre-ordered before September 21 and are not using Instant On power mode. Should you be one of these soldiers, you may have an incorrect file for the upcoming game, which will need to be deleted for Halo 5 to be re-installed.
If you've pre-ordered on or after September 21, you'll be good to go with required updates when they're available. Not sure if you have the incorrect "stub file" or not? There's an easy way to check to ensure you'll be able to overload the enemies with a few well-placed needler bolts in no time at all.
- Go to My games & apps
- Sort the game collection by selecting Installed - Sort by size
If your Halo 5: Guardians installation is more than 40GB, you're good to go. If it is less than 40GB, you'll need to delete and reinstall the game to replace the placeholder file.
Source: Halo Waypoint; Thanks, @zapellat, for the tip!