Console login fails for some users, and this does not affect all users on all consoles.
Error: console initialization error: The request failed with http status 400 bad request
To get around this, you can use the IP address of the site server, rather than the name
Add registry DWord values to HKLM\System\CurrentControlSet\Services\HTTP\Parameters
After adding these values and rebooting the server, all users stopped experiencing HTTP 400 errors.
This information came from the following website.