IMPORTANT NOTE: Xbox sign-ins may fail, as well, as a result of service host separation. To fix this issue:

1.Run the following from an admin Command Prompt (or edit the registry accordingly):REG ADD HKLM\SYSTEM\CurrentControlSet\Services\XblAuthManager /v SvcHostSplitDisable /t REG_DWORD /d 1 /f
2.Reboot the system, so that XblAuthManager now shares a service host process with Windows Update and Background Intelligent Transfer Service.

https://blogs.windows.com/windowsexperience/2016/10/07/announcing-windows-10-insider-preview-build-14942-for-pc/