The PC Halo Launcher / Halo App / HaloHub.exe has stopped working!
EDIT:
Someone found the solution.
FrankDaTank14 wrote:
I just figured this out on my machine 5 mins ago. The Halo App is no longer supported by Microsoft. If you delete it, then launch the game directly, it should run. Hope this helps.Windows 10 Halo app is being retired today - OnMSFT.com