nmap -oX brute-test -Pn -p 445 --script smb-brute -v --script-args=brute.firstonly=true 127.0.0.1 -d

...

NSE: Starting smb-brute against 127.0.0.1.
NSE: [smb-brute 127.0.0.1] SMB: Added account '' to account list
NSE: [smb-brute 127.0.0.1] SMB: Added account 'guest' to account list
NSE: [smb-brute 127.0.0.1] SMB: Login as \guest failed (NT_STATUS_LOGON_FAILURE)
NSE: [smb-brute 127.0.0.1] Remote operating system: Windows 7 Professional 7601 Service Pack 1
NSE: [smb-brute 127.0.0.1] Couldn't detect lockout policy: NT_STATUS_ACCESS_DENIED
NSE: [smb-brute 127.0.0.1] WARNING: couldn't determine lockout policy: Couldn't retrieve lockout policy: NT_STATUS_ACCESS_DENIED
NSE: [smb-brute 127.0.0.1] Trying to get user list from server
NSE: [smb-brute 127.0.0.1] MSRPC: Failed to enumerate users through LSA: NT_STATUS_ACCESS_DENIED
NSE: [smb-brute 127.0.0.1] MSRPC: Failed to enumerate users through SAMR: NT_STATUS_ACCESS_DENIED
NSE: [smb-brute 127.0.0.1] Couldn't enumerate users (normal for Windows XP and higher), using unpwdb initially
NSE: [smb-brute 127.0.0.1] Opening password list
NSE: [smb-brute 127.0.0.1] Starting the initial SMB session
NSE: smb-brute against 127.0.0.1 threw an error!
/usr/bin/../share/nmap/nselib/smb.lua:202: bad argument #2 to 'format' (number expected, got boolean)
stack traceback:
        [C]: in function 'string.format'
        /usr/bin/../share/nmap/nselib/smb.lua:202: in function 'smb.get_status_name'
        /usr/bin/../share/nmap/nselib/smb.lua:1285: in upvalue 'start_session_basic'
        /usr/bin/../share/nmap/nselib/smb.lua:1567: in function 'smb.start_session'
        /usr/bin/../share/nmap/scripts/smb-brute.nse:315: in upvalue 'check_login'
        /usr/bin/../share/nmap/scripts/smb-brute.nse:604: in upvalue 'initialize'
        /usr/bin/../share/nmap/scripts/smb-brute.nse:970: in upvalue 'go'
        /usr/bin/../share/nmap/scripts/smb-brute.nse:1079: in function </usr/bin/../share/nmap/scripts/smb-brute.nse:1067>
        (...tail calls...)