When launching an application on 4D server, if there is a conflict of port usage with another application, normally an alert like the following would appear:

Falied to launch DB4D Server. Please make sure that the port assigned to the DB4D Server is not used by another application.



However, if running 4D server as a service, the alert would not appear because the server is running in the background. That is why it is important, before restarting a service to run 4D server, to check that the port it is using is not already occupied.