Help with uploading files needed

Hi - I have been using smart ftp for about a year to upload files to my websites.

But today I cannot do this - whenever I try to access the host for my website through smartftp I get the following message:

Timeout (20s).
Active Help: https://www.smartftp.com/support/kb/74
Client closed the connection.
Automatic failover of data connection mode from "Passive Mode (PASV)" to "Active Mode (PORT)".

I have no real great "techie" knowledge and so do not understand what it is telling me.

Can someone please give me some help and tell me straightforward what I need to do - I cannot understand the online manual.

In return I have lots of valuable ebooks and information on internet marketing that I will happily share with you.

Thanks

John