Hey All-
There is a new patch for Halo Wars DE that just released. I don’t know the patch notes, but one thing it did fix for me is the ability to play on-line. For some reason, some users were not able to play on-line with the game after it came out of early access. Several posts in the Support Forum were created, but left unanswered. Some users suggested it was a Gamertag issue, so I tested with my wives GT and sure enough I was able to play on-line, but when I used my own tag, I would get an immediate disconnected error.
With today’s update, this issue is no longer a problem. So if you were one of the few that had this issue, it is now resolved.