RoundCube login Webpage can't connect

[yayaigo]

In taiwan,we can go to http://<Domain Name>:84/roundcube/
but in japen,nini's notebook  can't go to
http://<Domain Name>:84/roundcube/
(it can go to http://<Domain Name>)

chrome will show "This web page can't use",

I click the "detail information" button,it say "err_connection_timed_out"
I don't know how to show the bug in taiwan,and how to find the
problem,fix it.

Can anybody know how to fix it?

[SKaero]

Port 84 is most likely being blocked by a firewall, I'd recommend you change ports or access the installation via a VPN.