Your ftp client settings:

Set your connection to FTP, port 21 by default:

Connect to www.onlinefilefolder.com

Try enabling or disabling PASSIVE MODE.
From EDIT / SETTINGS / FIREWALL SETTINGS, check the Passive Mode box. This will usually solve any connection issue.
This will enable a ‘firewall friendly’ session:

For most FileZilla questions and support, visit the Filezilla documentation page.
Please email Support@onlinedatabackup.us with any questions.