one of the accounts does not work on fortnite and it is saying unable to sign into your...

Everything matches email wise. When we try and log into fortnite it says unable to sign into your account for xbox live

When I go to play Fortnite it says unable to sign into Xbox live but I have Xbox ultimate which has Xbox live so I don’t know why it’s not working

Happens to me sometimes, need to wait till Xbox live is fully loaded before signing in, if that doesn't work, log out of your account, quit Fortnite, start Fortnite while not signed in , You'll
be prompted to log in , Once logged in, your account should work -

Hello, first it's a pleasure to be able to help you today.

My name is welcome to the community.

Hello Mustufa, if you play on the PC, and installed Fortnite through Epic Launcher you would have to place your account on an Xbox One console so you can validate the item by the code you reposted.

Because you have a Microsoft account linked to your Epic account, try sign in through Fortnite online via XCloud to see if the item is validated in your account.

https://www.xbox.com/en-US/play/games/fortnite/...

If it doesn't work, you'll still need to sign in to an Xbox One console with your account.

This worked for me and hopefully it does for you, unfortunately chat support was unable to assist.

Any how - if you are unable to access your messages on your Xbox App or your messages from Xbox.com there is currently a system message that is on your account that can be viewed on your smart device or xbox platform. I was unable to delete it while viewing
it on the Xbox One, to work around this I went on smart glass through my tablet where I was able to delete the system message from my account. After I did this I signed out of the Xbox App on my PC and signed back in and BOOM, back to normal.

I did not have to sign out of xbox.com, i simply clicked the link for messages and it was working as well.

Good luck!