This is the Happy Wars management team.
Since September 18 at 1:00 (UTC) there is an issue with the login on the Xbox One version of the game.
Before the Title Screen login, a message that says ” Unable to access the Happy Wars network save service. Please check your network status and try again later.” appears and makes it not possible to log in.
For those who experienced this issue, restarting your Xbox One and trying again after a while might solve the problem.
We are aware of the situation and we are doing everything possible to solve it as soon as possible.
Thank you for your patience understanding.