ServiceLoader with UrlClassLoader not finding service

I am trying to load plugins from a certain jar file using the java ServiceLoader with an UrlClassLoader, but I just cannot seem to get it to find my plugin classes. Building both modules works, but whenever I run the code below, I get a java.util.NoSuchElementException, even though the file path is correct and I do not see where I messed up

I have to modules in my IntelliJ project, Test (The application loading the plugin and also providing the ServiceProvider) and PluginTest (The plugin to be loaded).

This is a screenshot of the structure of the Test module:

And here is a screenshot of the structure of the PluginTest module:

Here is the ServiceProvider PluginProvider:

package net.lbflabs;

public abstract class PluginProvider {

    public abstract String getSecretMessage(int message);
}

This is the plugin that extends this class:

package net.lbflabs.plugins;

import net.lbflabs.PluginProvider;

public class PluginClass extends PluginProvider {
    @Override
    public String getSecretMessage(int message) {
        return "Here is my secret.";
    }
}

Here is the main class that loads the plugin:

package net.lbflabs;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ServiceLoader;

public class Main {

    private static String path = "C:/Users/jacke/IdeaProjects/Tests/out/artifacts/PluginTest_jar/PluginTest.jar";

    public static void main(String[] args) throws MalformedURLException {
        System.out.println("Initializing... \nPreparing to load JAR from Path " + path + "...");
        File file = new File(path);
        System.out.println(file.exists()); //Prints true, so file does exist
        URLClassLoader c = new URLClassLoader((new URL[]{file.getAbsoluteFile().toURI().toURL()}));
        ServiceLoader<PluginProvider> loader = ServiceLoader.load(PluginProvider.class, c);
        PluginProvider p = loader.iterator().next(); // Throws the java.util.NoSuchElementException
        System.out.println("Secret message in plugin: " + p.getSecretMessage(1));
    }
}

Here is the output when running the Tests module:

"C:\Program Files\Java\jdk-14.0.1\bin\java.exe" "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2020.3\lib\idea_rt.jar=50330:C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2020.3\bin" -Dfile.encoding=UTF-8 -classpath C:\Users\jacke\IdeaProjects\Tests\out\production\Tests net.lbflabs.Main
Initializing... 
Preparing to load JAR from Path C:/Users/jacke/IdeaProjects/Tests/out/artifacts/PluginTest_jar/PluginTest.jar...
true
Exception in thread "main" java.util.NoSuchElementException
    at java.base/java.util.ServiceLoader$2.next(ServiceLoader.java:1310)
    at java.base/java.util.ServiceLoader$2.next(ServiceLoader.java:1298)
    at java.base/java.util.ServiceLoader$3.next(ServiceLoader.java:1396)
    at net.lbflabs.Main.main(Main.java:19)

Process finished with exit code 1

The service file in the PluginTest module I believe is correctly named (net.lbflabs.PluginProvider) and contains the valid class name (net.lbflabs.plugins.PluginClass). If it was incorrect, IntelliJ would probably find the issue since when I introduce a typo I get warnings.

If someone needs it, I can provide the whole project as .rar (please tell me how you want me to share it, e.g. I create a onedrive link)

PS: I have already asked this question here, but since I was working on a bigger project and hesitant to share all the code in it (and since the only answer I got did not work, probably due to not enough info from me), I wanted to repost the issue with a minimum workable example that throws the same exception, I hope that is fine.

One thing I notice is that you construct a classloader which only contains 1 class. With this it won't be able to create a proper class hierarchy and most likely fail. Instead pass the current Classloader as the parent to your URLClassLoader.

ClassLoader parent = PluginProvider.class.getClassLoader();
URL[] urls = new URL[] { file.getAbsoluteFile().toURI().toURL()};
URLClassLoader c = new URLClassLoader(urls, parent);

Now a proper hierarchy should be able to be constructed.

Another thing is in your project structure your META-INF directory isn't under the src directory containing the sources for the project. Which means Intellij will leave them out of the jar. So you are basically adding a jar without the proper files. It contains only the class and not META-INF/services/net.lbflabs.PluginProvider.