Xbox one issue with green screen

This is the first and easiest way you should try to get Xbox One green screen fixed.

• Press and hold the Power button on the console for about 10 seconds.
• Then start console again.
• Xbox One will start appropriately without the green loading screen issue.

OK try a offline update to refresh the OS https://support.xbox.com/en-US/xbox-one/console/system-updates-solution

Sadly, my brother had that issue. I fixed his xbox and got all his stuff with no issue. I simply did a factory reset. It gave me the option of saving games and app data. I clicked it and all i needed to get his gt and stuff back was to remember his wmail
and password. Then we checked his most played and most data game he had to make sure it was good. He still has all his stuff and his xbox was fixed. Granted took an hour or so how to figure this out since it was my first having to do that but nonetheless,
i still got his stuff back

Did it stall at 50%? Because its been at that spot for quite som time. Maybe thirty minutes or so. So far.

Are you in the insider program at all?.