I was trying to make a JavaFX project with Kotlin, Gradle on IntelliJ IDEA.
Using Java 17.

At first, I didn’t used module-info.java, and it worked well, but it warned me

"WARNING: Unsupported JavaFX configuration: classes were loaded from 'unnamed module @34277041'"

So I added module-info.java to the project:

module org.example.javafxdemo {
    requires javafx.controls;
    requires javafx.fxml;
    requires kotlin.stdlib;

    opens org.example.javafxdemo to javafx.fxml;
    exports org.example.javafxdemo;
}

project structure:

project
+ src
  + kotlin
    + org.example.javafxdemo
      + HelloApplication.kt
    + module-info.java

But then it causes error:

Error occurred during initialization of boot layer
java.lang.module.FindException: Module javafxdemo.main not found

What I tried:
I made a new Kotlin Project, includes only main.kt and module-info.java, and it warned same warning, so I think module-info.java is the problem, but JavaFX requires module-info.java..
I tried putting the source files of both languages in the same source directory, but it didn’t work.

Thank you so much!