Problem accessing samba share

Hi all,

I have samba 4.6.2 on RHEL 7.

We have a production server still on Windows 2003 R2.

I need the Windows server to access one of the Samba shares, but I'm having problems. It was previously connected to a Samba share on a RHEL6 platform with older Samba.

I have tried the share credentials from a Windows 10 box with success, so I suspect I either need to increase Samba 4's compatibility level (if possible via the config) or change something in the Windows server's registry/policy.

Does anyone have any experience with this, and/or any advice?

My smb.conf:

"
[global]
security = user
passdb backend = tdbsam

case sensitive      = yes
dns proxy           = No
domain master       = No
#encrypt passwords  = yes
map to guest        = Bad User
load printers       = no
local master        = No
log file            = /var/log/samba/%m.log
log level           = 1
max log size        = 50
preferred master    = No
server string       = DB3 Samba Server
smb ports           = 139 445
unix extensions     = no
workgroup           = xxxxx

[edi]
browseable = no
create mode = 0700
directory mask = 0700
follow symlinks = yes
path = /sambashares/edi
read only = No
guest ok = No
valid users = jbloggs, ediuser
wide links = yes
"

Thank you

Elliot