Just for other people's benefit. If the error is a 401.1 Unauthorized and your error code matches 0xc000006d, then you're actually running into to a security "feature" that blocks requests to FQDN or custom host headers that don't match your local machine name:
Follow this support article to fix the issue:
https://webconnection.west-wind.com/docs/_4gi0ql5jb.htm (original, now defunct: http://support.microsoft.com/kb/896861)
From the support article, to ensure it doesn't get lost:
The work around is a registry hack that disables this policy explicitly.
To perform this configuration manually find this key in the registry on the server:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsaand edit or add a new key:
DisableLoopbackCheck(DWORD)then sent the value to 1 to disable the loopback check (local authentication works), or to 0 (local authentication is not allowed).
Or more easily you can use Powershell:
New-ItemProperty HKLM:\System\CurrentControlSet\Control\Lsa -Name "DisableLoopbackCheck" -Value "1" -PropertyType dwordIt looks like recent builds of Windows 10 (1803 and later?) also require this configuration setting in order to authenticate locally.
This one took me awhile because everyone else's comments here failed to help me. I found this article and it fixed it!