Resolution:
Check whether the shutdown port or any of the other ports used by Administrator are already in use by another program.
On UNIX you can use netstat or a similar command.

You can check the ports that Administrator uses, by looking in the file:
    TIBCO_HOME/administrator/domain/&ltdomain name>/tomcat/conf/server.xml

In case the ports are in use by any other application you would see the error in the tomcat.log present in &lttibco_home>/administrator/domain/&ltdomain name>/tomcat/logs