Can't Signin to My Xbox app on Surface 2

I was having this problem on my Xbox One, Surface Book, and my Lumia Icon running Windows 10. I got an update on my Xbox which seemed to fix the issues with that, but the problem persists on my phone and my Surface Book. I can't play Spartan Strike or Spartan
Assault on my Surface Book, and I can't use the Xbox Extras app on my phone.

F00xm4n I had this same problem with my windows surface 2 now I have a iPad Air it works fine I think I did get it to work on my surface 2 but can't remember how I wouldnt worrie bout the companion app it only shows the map on battlefield and ur hardly look
at it

Me too. I can't sign in with Microsoft Jackpot on my Surface Book, but the game works fine on my Surface 3. Deleting and reinstalling the app on my Surface Book made no difference.

You can't change a gamertag into a previously owned one but you could sign in to the Windows 10 Xbox app with the old one though.

This link will give you you all the info you need to sign in to the Xbox app on Windows 10.

support.xbox.com/.../signin-xbox-app-on-windows-10

would start to load then just close & go back to start screen or said can't login to Xbox.

I am using surface RT 2 running windows 8.1.

I uninstalled it reinstalled it, now it says app can't open 😢