From the FreeNAS Documentation, Release 9.3.1 (I'm almost sure it still applies for this):
If the CIFS service will not start, run this command from Shell to see if there is an error in the configuration:
testparm /usr/local/etc/smb4.conf
You can post the results here.
Here are the results:
Load smb config files from /usr/local/etc/smb4.conf
WARNING: The "null passwords" option is deprecated
Processing section "[sysvol]"
Processing section "[netlogon]"
Processing section "[VMWARE]"
Loaded services file OK.
Server role: ROLE_ACTIVE_DIRECTORY_DC
Press enter to see a dump of your service definitions
# Global parameters
[global]
dos charset = CP437
workgroup = OTCSOLUTIONS
realm = OTCSOLUTIONS.LAN
server string = FreeNAS Server
server role = active directory domain controller
map to guest = Bad User
null passwords = Yes
obey pam restrictions = Yes
passdb backend = samba_dsdb
logging = file
max log size = 51200
server max protocol = SMB2
max protocol = SMB2
protocol = SMB2
time server = Yes
deadtime = 15
kernel change notify = No
max open files = 231095
hostname lookups = Yes
load printers = No
printcap name = /dev/null
disable spoolss = Yes
lm announce = Yes
dns proxy = No
panic action = /usr/local/libexec/samba/samba-backtrace
dns forwarder = 192.168.10.20
nsupdate command = /usr/local/bin/samba-nsupdate -g
rpc_server:tcpip = no
rpc_daemon:spoolssd = embedded
rpc_server:spoolss = embedded
rpc_server:winreg = embedded
rpc_server:ntsvcs = embedded
rpc_server:eventlog = embedded
rpc_server:srvsvc = embedded
rpc_server:svcctl = embedded
rpc_server:default = external
winbindd:use external pipes = true
idmap_ldb:use rfc2307 = yes
idmap config *: range = 90000001-100000000
idmap config * : backend = tdb
acl allow execute always = Yes
create mask = 0666
directory mask = 0777
directory mode = 0777
ea support = Yes
directory name cache size = 0
map archive = No
map readonly = no
store dos attributes = Yes
strict locking = No
dos filemode = Yes
vfs objects = dfs_samba4 acl_xattr
[sysvol]
path = /var/db/samba4/sysvol
read only = No
vfs objects = zfs_space zfsacl
zfsacl:acesort = dontcare
nfs4:chown = true
nfs4:acedup = merge
nfs4:mode = special
[netlogon]
path = /var/db/samba4/sysvol/otcsolutions.lan/scripts
read only = No
vfs objects = zfs_space zfsacl
zfsacl:acesort = dontcare
nfs4:chown = true
nfs4:acedup = merge
nfs4:mode = special