No Access to NETLOGON and SYSVOL with Samba 4.3.9-Ubuntu on Ubuntu Server 16.04

On my Linux box I am ruing the new Ubuntu Server 16.04 LTS 64-bit (Xenial Xerus) operating system. A new big capacity hard drive has been added to it lately, hence I wished to use the box as a File Server and Domain Controller for Windows workstations, as well. To achieve the goal, this site was my guide - http://blogging.dragon.org.uk/samba4...-ubuntu-14-04/. Everything seems to be OK except of after this command is issued: smbclient //localhost/netlogon -UAdministrator -c 'ls'.

Instead of getting something like this:
------------------------------------------------------------
Enter Administrator's password:
Domain=[BLACK] OS=[Unix] Server=[Samba 4.1.6-Ubuntu]
. D 0 Sat May 9 12:20:08 2015
.. D 0 Sat May 9 12:20:14 2015

41773 blocks of size 262144. 27672 blocks available
------------------------------------------------------------
I can only see this error: NT_STATUS_OBJECT_NAME_NOT_FOUND listing *. As DNS Backend I am using BIND 9.10.3-P4-Ubuntu. The Samba version is Version 4.3.9-Ubuntu.

Commands kinit and klist are all working great. Even I can see the shares in Windows, but no access to them although my workstation is joined into the domain and I am logged on as a domain admin. The Active Directory can be managed from workstation without any troubles, too. Only the shares including sysvol and netlogon and all others I created caot be accessed at all. That's weird.

I did install Samba4 as a DC many times before on Ubuntu Server 14.04.4 LTS. Everything was always working great. Can someone explain what can be wrong in my configuration and help to solve this unpleasant issue? Is it a bug of Samba 4.3.9-Ubuntu, or Ubuntu Server 16.04 LTS is the reason for this strange behavior?