samba - Oct 2018 - Error in LDB after upgrade from Ubuntu16 to Ubuntu18

Hello!

I had installed the SAMBA4/AD v4.3.8 in UBUNTU_16
So I did the upgrade to UBUNTU_18 using command 'do-release-upgrade' and
the upgrade finish sucessfully. The SAMBA4/AD migrate to v4.7.6
I did several tests in the AD and everything was working
But after restarting a few times, the error below occurred:


root at gserv2:~# *samba-tool  user list*
ldb: unable to stat module /usr/lib/x86_64-linux-gnu/samba/ldb : No such
file or directory
ldb: WARNING: Module [samba_secrets] not found - do you need to set
LDB_MODULES_PATH?
ldb: Unable to load modules for /var/lib/samba/private/secrets.ldb: (null)
ldb: unable to stat module /usr/lib/x86_64-linux-gnu/samba/ldb : No such
file or directory
WARNING: Module [samba_dsdb] not found - do you need to set
LDB_MODULES_PATH?
Unable to load modules for tdb:///var/lib/samba/private/sam.ldb: (null)
ERROR(ldb): uncaught exception - None
  File "/usr/lib/python2.7/dist-packages/samba/netcmd/__init__.py",
line
176, in _run
    return self.run(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/samba/netcmd/user.py", line
482,
in run
    credentials=creds, lp=lp)
  File "/usr/lib/python2.7/dist-packages/samba/samdb.py", line 57, in
__init__
    options=options)
  File "/usr/lib/python2.7/dist-packages/samba/__init__.py", line 114,
in
__init__
    self.connect(url, flags, options)
  File "/usr/lib/python2.7/dist-packages/samba/samdb.py", line 72, in
connect
    options=options)
root at gserv2:~#


Please, anyone know how to help me?

Thanks,
Anderson Hoffmann