Here is an example of what happens when calling Application.launch more than once: java.lang.IllegalStateException: Application launch must not be called more than once
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:162)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:143)
at javafx.application.Application.launch(Application.java:191)
at Line_18.startApp(Line_18.kts:2)
at Line_18.startApp$default(Line_18.kts:4)