Unable to connect to FTP: Service not available, remote server has closed connection

Symptoms

Unable to log in to a domain via FTP, the following error appears:

    421 Service not available, remote server has closed connection

Cause

Connection to 21 port is closed. Wrong configuration in " /etc/proftpd.conf " file.

Resolution

1. Try to connect to FTP and check log for errors:

   # tail -f /var/log/messages
   
   proftpd[11783]: Fatal: ScoreboardFile: : unable to use '/var/run/proftpd/scoreboard': No such file or directory on line 45 of '/etc/proftpd.conf'
   xinetd[2312]: EXIT: ftp status=1 pid=11783 duration=0(sec)
   

2. If you see the error above, make sure that directory " /var/run/proftpd " exists.

   [root@apache ~]# ls -la /var/run/proftpd
   ls: cannot access /var/run/proftpd: No such file or directory
   

3. If there is no such directory, create it manually:

   [root@apache ~]# mkdir /var/run/proftpd/
   [root@apache ~]# ls -la /var/run/proftpd/
   total 8
   drwxr-xr-x  2 root root 4096 Mar 19 12:41 .
   drwxr-xr-x 18 root root 4096 May  6 15:38 ..