If you receive the following error message in the /var/log/messages file while restarting the pure-ftpd service, the problem is in the ftp configuration file at /etc/pure-ftpd.conf
pure-ftpd: (?@?) [ERROR] Configuration error: Illegal load limit: 0
Edit the pure-ftp configuration file and search for
MaxLoad = 0
change it to
MaxLoad = 4 (value should be above 0)
Save the file and restart the service:
/etc/init.d/pure-ftpd restart