[Samba] Samba4 server is not accessible for logon from Windows 2008R2 SP1.

[CpServiceSPb .]

There is Samba4 4.7.2 acting as standalone server on Ubuntu 14.04.x64.
Also there is Windwos 2008R2 SP1 acting as DC in the same network.
And also Windows XP/7 are in this network.
Logon to Samba4 is accessible from Windows XP and Windowx 7 but not
accessible from Windos 2008R2.
As logon to Windows clients is accessible from Windows 2008R2.
Username and password is asked by Samba and provided from Windows 2008R2
during logon to Samba4 server but it asks username/password again and again
and not accept provided one.
That is logon is unsuccessfull.
The same situation was with Samba4 beginning from 450 version.
Regarding versions prior, don' t remember exactly.
What is the way to solve issue ?