I am using RAD 7.5.0 and the websphere server v6.1. When i start the server in debug mode, it displays a error message states that
'Starting WebSphere application server in localhost; has encountered a problem. JVM debug port #### is in use.
What is the problem? How to resolve this?
It simply means that the debug port is currently in use. Do you have any other IBM products already running on that box? Does this happen when you start your server for the first time or for subsequent tries?
One suggestion would be to hunt down rogue hanging Java processes and kill them (in case you don't need them) to resolve this.
i also frustrated many times because of this eroor.. Finally found out the solution
To resolve this problem you will need to do the following to all of your subsequent servers:
1.Start the server in 'normal' mode (i.e. non-debug mode).
2.Launch the Administrative console and log in.
3.Expand 'Servers', click on 'Application Servers', and then your server instance (typically 'server1').
4.On the 'Configuration' tab expand 'Java and Process Management' and then click on 'Process Definition'.
5.Under the 'Additional Properties' header, click on 'Java Virtual Machine'.
6.Scroll to the bottom of the page, locate the 'Debug Arguments' text field, and increment the 'address' property at the very end of the string so it will use a unique port value.
7.Save your changes, exit the administrative console, stop the server, and then start it in debug mode
来源：https://stackoverflow.com/questions/4592520/rad-jvm-debug-port-is-in-use