Halo Wars 2 add-ons

Please follow the steps mentioned here (section: troubleshooting add-ons) => Find your games and add-ons on Xbox | Xbox Support. After following the previous steps, please over the following ones:

Access Settings > Network Settings > Advanced Settings > Alternate Mac Address > Clear it and the console should restart. It would definitely help if you could restart the internet router while the console is restarting.

After going through the troubleshooting steps mentioned, I invite you to perform a quick power cycle by turning off the console and then unplugging all the cables. After 2 to 3 minutes, re-plug them back again, then restart your console.

In case the issue still persists, the next step would be to perform a reset on the console. To do so you will need to follow the steps below to perform a reset on the Xbox :

Settings > System > Console Info > Reset This Xbox > Reset and Keep my Games and Apps.

Note =>The "Reset and Keep my Games and Apps" option will not cause losing your games, but please be aware that you need to be completely aware of the email address as well as the password of your account before going for it because it will require you to sign in to the account.

Do a search for just Halo Wars 2. In the results it should show "Halo Wars 2: Demo, Halo Wars 2, Halo Wars 2: Standard Edition" Try clicking the one in the middle and see if that one will start the install for you. I noticed if I choose the standard edition
it wants to install on the console.

you get Halo 1,2,3,4 and Reach, Halo 3ODST must have been purchased as an add on, it does not include Halo 5, Halo wars 1 and 2

lol there was no halo in "halo wars,, halo3 odst, and halo reach.. those were adjecent add on campaigns. there was only halos 1,2, and 3. first 2 were destroyed.

yeah add me too, into all things Halo, including Halo wars, GOW1, 2 and soon 3, into Forza 3 atm too