Koei Tecmo has recently suffered a cyber attack which has caused the forum login details for 65,000 of its users to be leaked. As a result of this, both the American and European Koei Tecmo websites have been taken down, and there is no clear indication as to when they might resurface. The error message displayed when trying to view the site says that the company is currently investigating the issue and has suspended access in the meantime.
We're hoping that these issues can be resolved in the near future.
Thanks, Nintendo Life.