Downgrading only samba package from 4.6.2-X to 4.4.4-14.el7_3 causes smb service crash.

Issue

• I updated the samba package from 4.4.4-14.el7_3 to 4.6.2-X, but I needed to revert to the 4.4.4-14.el7_3 due to a problem. I downgraded only samba package.

  # yum update samba
  # yum downgrade samba-4.4.4-14.el7_3

• The smbd daemon crashes and multiple core files are dumped while starting up the service.

  # systemctl start smb
  # systemctl status smb
  ● smb.service - Samba SMB Daemon
     Loaded: loaded (/usr/lib/systemd/system/smb.service; disabled; vendor preset: disabled)
     Active: failed (Result: core-dump) since Wed 2017-10-04 15:00:00 JST; 10min ago
    Process: 3878 ExecStart=/usr/sbin/smbd $SMBDOPTIONS (code=dumped, signal=ABRT)
   Main PID: 3878 (code=dumped, signal=ABRT)
     Status: "smbd: ready to serve connections..."

  Oct 04 15:00:00 sambasvr smbd[3878]:    #9 /lib64/libtevent.so.0(tevent_common_loop_wait+0x1b)...2fb]
  Oct 04 15:00:00 sambasvr smbd[3878]:    #10 /usr/sbin/smbd(main+0x15d4) [0x7fc0e6eadad4]
  Oct 04 15:00:00 sambasvr smbd[3878]:    #11 /lib64/libc.so.6(__libc_start_main+0xf5) [0x7fc0e29b7c05]
  Oct 04 15:00:00 sambasvr smbd[3878]:    #12 /usr/sbin/smbd(+0x7ea6) [0x7fc0e6eadea6]
  Oct 04 15:00:00 sambasvr smbd[3878]: [2017/10/04 15:00:00.065096,  0] ../source3/lib/dumpcore....ore)
  Oct 04 15:00:00 sambasvr smbd[3878]:   dumping core in /var/log/samba/cores/smbd
  Oct 04 15:00:00 sambasvr smbd[3878]:
  Oct 04 15:00:00 sambasvr systemd[1]: smb.service: main process exited, code=dumped, status=6/ABRT