[Samba] Samba4 Kerberos Authentication Error

[Marco Shmerykowsky]

I'm trying to setup a Samba4 Active Directory server.

I've gotten the server running, the IP addresses resolve
properly.  The Windows10 client can join the domain.
I've run the basic checks that seem to be listed
on the samba wiki and get the expected results.

I've modified nsswitch.conf to include winbind on the
passwd and group lines.

I've made sure all machines are pointing to the same
NTP server so that time is synched

I've created a user using -> samba-tool user create jdoe

I've added the computer using -> samba-tool computer create MACHINE01

I've created a "test-share" with ownership set to the
group "Domain Users":

[Test-Share]
        path = /home/test-share
        writable = yes
        create mode = 0770
        directory mode = 0770
        guest ok = no

When I run Server Manager in Win10 I get an error that
states: "Kerberos authentication error"

When I try to login with the user, Windows gives me this:

"We can't sign you in with this credential because your
domain isn't available.  Make sure your device is connected
to your organization's network and try again."

Login authentication didn't seem to work before I
added the test-share either.

What did I miss?