I downloaded the Halo App and Halo 5 Forge on my PC and tried to play. Forge told me I had to sign into an account before I was able to play and when I tried to sign in on the app it just brings up a black pop-up for a bout 2 seconds and then it closes. How do I fix this?
If you just want to play, and not actually use the Halo app, uninstall it and then just launch the game by running the Forge app.
Can you sign in on the Xbox Windows app?