There are several common problems that result in System Manager being unable to connect to InterChange Server.
Examine the name exactly as it appears in whatever interface is used to start the server. On Windows, the server name is commonly supplied as a parameter to the start_server.bat batch file. The value is in the Target field of the shortcut that invokes the batch file. On Unix platforms you manually specify the name of the InterChange Server instance.
Examine the name as it is displayed in the InterChange Server logging output. The log entry "<server name>" is ready" indicates that the server has started and by what name it can be identified. You must specify the correct user name, which is admin.