This may seem a bit of a silly question … is your server and client of the same version? I have had the error you noted once before when the server and client were of different versions (or at least something similar).
Are you sure your server allows connections on port 13xxx that your version of Cloverleaf uses (firewall perhaps blocking the port) from remote machines.
Is your Cloverleaf servers host server running? Under UNIX you have to start it with hciss -s h if it is not in the system startup scripts. Under Windows the service needs to be running.
Also, with versions of Cloverleaf before 5.5 we could not get basic security to work on Linux (dunno about Mac). Something goes wrong with the certificate exchange.
Let me know what you find …
I will look at my notes and see if I can find other possible issues.
Frans