client closed connection

I can't seem to connect and don't understand what client closed connection signifies.
Here is the thread:
SmartFTP v4.0.1054.0
[20:22:07] Resolving host name ""
[20:22:07] Connecting to Port: 21
[20:22:07] Connected to
[20:23:07] Timeout (60s).
[20:23:07] Active Help:
[20:23:07] Client closed the connection.
[20:23:07] Connect failed. Waiting

I've just downloaded the new version because I hoped that would save me, but still same problem.
Hope you can tell me how to update my website.

Add SmartFTP to the exceptions in your software firewall and antivirus product.