You can bypass this error by setting up the FTP connection in the Site Manager.
In FileZilla, click on File > Site Manager > New Site and enter in the following settings:
General Tab:
Host: [The same IP address/domain name you were using]
Port: 21
Protocol: FTP
Encryption: Only use plain FTP
Logon type: Normal
Username: [your FTP username]
Password: [your FTP password]
Transfer Settings Tab:
Transfer mode: Default
Limit Number of simultaneous connections: Ticked
Maximum number of connections: 8
If you continue to have issues with connecting to your account via FTP after setting the above in FileZilla, please Open a Ticket to our Support team with a copy of the activity log in FileZilla and the team will be able to check this further for you.