ftp can not connect to server

[Toeki]

I don't know what happened with cpanel but none of our clients can connect to the server through ftp.
I have upgraded cpanel and the problem still exist - how can this problem be solved? I need to get this solved asap before our clients start to leave.

Thanks.

[AndyReed]

I don't know what happened with cpanel but none of our clients can connect to the server through ftp.

Any error message(s) when trying to login or upload? Did you run /scripts/ftpup --force