Deploying Unity game to XBox One Creators - XBox veto error?

For anyone coming here after searching "XBox Veto 8015DC12", the fix is to set the Sandbox setting on the XBox One in Dev mode ("Change sandbox") to the Sandbox ID that is in the XBox Live configuration in Unity.

This shows me building a Unity game for UWP and deploying it for Windows 10 and the XBox One. The XBox Live login works for the WIndows PC deploy, but throws an error on the XBox One retail console in Dev mode. ... https://www.youtube.com/watch?v=wsacYhbwZKk