Customer is using a broker with a non standard/non default port.
Harweb is able to display the login screen, but login attempts generate the following error:
Comm error: -306
Release : 13.0.3
Component : CA HARVEST SCM GUI/Harweb
Rtserver has been configured to use a nondefault port.
Default port is 5051.
Customer needs to implement the rtserverport option
In some such scenarios, one may have configured Harvest to use a different default port number instead of 5101, so in such a situation, one will need to configure Harweb for this new port number as well.