Sambaはフォルダを共有できません–名前「全員」をシドに変換できませんか？

すでに数日前にサンバ共有が成功した後、今日も同じことがありますが、次のエラーが発生しました：

'net usershare' returned error 255: net usershare add: cannot convert name "Everyone" to a SID. 
The connection was refused. Maybe smbd is not running.

sambaサービスを開始/再起動しようとすると、次のようになります

$ sudo service samba status
 * nmbd is running
 * smbd is not running
$ sudo service samba start
$ sudo service samba restart
$ sudo service samba status
 * nmbd is running
 * smbd is not running

私の/var/log/samba/smbd.log

[2014/01/15 16:21:46,  0] smbd/server.c:1072(main)
  smbd version 3.6.18 started.
  Copyright Andrew Tridgell and the Samba Team 1992-2011
[2014/01/15 16:21:46.426302,  0] smbd/server.c:1128(main)
  standard input is not a socket, assuming -D option
[2014/01/15 16:21:46.428538,  0] auth/auth_util.c:708(get_guest_info3)
  SamInfo3_for_guest: Unable to locate guest account [guest]!
[2014/01/15 16:21:46.428578,  0] smbd/server.c:1251(main)
  ERROR: failed to setup guest info.

私の/etc/samba/smb.conf

$ grep -E "^[^#;].*" /etc/samba/smb.conf
[global]
   workgroup = WORKGROUP
   server string = %h server (Samba, Ubuntu)
   dns proxy = no
   log file = /var/log/samba/log.%m
   max log size = 1000
   syslog = 0
   panic action = /usr/share/samba/panic-action %d
   encrypt passwords = true
   passdb backend = tdbsam
   obey pam restrictions = yes
   unix password sync = yes
   passwd program = /usr/bin/passwd %u
   passwd chat = *Entersnews*spassword:* %nn *Retypesnews*spassword:* %nn *passwordsupdatedssuccessfully* .
   pam password change = yes
   map to guest = bad user
        usershare allow guests = yes
        username map = /etc/samba/smbusers
        security = user
        guest ok = yes
        ; guest account = nobody
  usershare max shares = 100
  usershare owner only = False

承認された回答：

問題はユーザー名にありました。この行のコメントを外しました：

guest account = nobody

nobody持っていない 私のシステムのユーザーで、今は正常に動作しています。