After upgrading my FreeNAS server to the latest version the other evening I started to experience some issues with my Windows 10 workstation being able to authenticate with and then access the files on the FreeNAS Server.
After some checking around it became apparent that there was an issue with the user authentications. The following appeared to fix the issue –
Change the logging level on the FreeNAS server for the SMB service so that the issue was visible – Services > SMB > Log Level ‘Normal’
View the log file and see the authentication issues – tail -f /var/log/samba4/log.smbd
Verify that your password in Windows and on the FreeNAS server match.
Delete any shares on the Windows client that may have cached credentials – net use * /d
You may also want to look at setting ‘ntlm auth = yes’ in the ‘Auxiliary parameters:’ section of the SMB Services Configuration