Natural for Visual Studio Code 1.2.1 | Prerequisites | Preparing the Natural Output
 
Preparing the Natural Output
To support Natural input and output when a Natural application is executed or debugged, the extension includes a Tomcat server that contains the required components. When the extension is activated for the first time, it automatically extracts the Tomcat server to the %LOCALAPPDATA%\Tomcat folder.
Whenever the extension is activated, it automatically starts the Tomcat server. When the extension is deactivated (for example, when Visual Studio Code is closed), it automatically shuts down the Tomcat server.
Note: 
By default, the Tomcat server listens on port 8080. This port is specified by the Natural preference natural.io.appserver.port=8080.
Changing the Port of the Tomcat Server
To change the port, adapt the following entry in %LOCALAPPDATA%\Tomcat\apache-tomcat-*\conf\server.xml:
<!-- NaturalONE: set address=127.0.0.1 - avoid fire wall entries -->
<Connector address="127.0.0.1" port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443"
maxParameterCount="1000"
/>
Changing this port also implies setting the natural.io.appserver.port preference to the new value. See also Preparing the Workspace.
The Tomcat server uses the port specified by the natural.io.port preference (default: 3500) to communicate with the Natural debug adapter. If this port is already in use, change it to a different port. See also Troubleshooting.