class file has wrong version 65.0, should be 61.0

[poach3r]

Describe the bug In IntelliJ IDEA Ultimate Edition, I can successfully add the LITIENGINE library and use it in my project without seeing any syntax errors, however it fails to compile. This happens regardless of build system used.

// ./src/Main.java
import de.gurkenlabs.litiengine.Game;

public class Main {
    public static void main(String[] args) {
        System.out.println("Hello world!");
        Game.init(args);
        Game.start();
    }
}

Stack Trace

java: cannot access de.gurkenlabs.litiengine.Game
  bad class file: /$MAVEN_REPOSITORY$/de/gurkenlabs/litiengine/0.8.0/litiengine-0.8.0.jar!/de/gurkenlabs/litiengine/Game.class
    class file has wrong version 65.0, should be 61.0
    Please remove or make sure it appears in the correct subdirectory of the classpath.

To Reproduce Steps to reproduce the behavior:

1. Install jetbrains.idea-ultimate from nixpkgs
2. Create a new project
3. Import any LITIENGINE version
4. Use LITIENGINE in your project
5. Build the project

Expected behavior The project should compile without any errors.

Screenshots If applicable, add screenshots to help explain your problem.

Your System:

• OS: NixOS 23.11
• LITIENGINE version: 0.8.0
• Java JDK/JRE version: openjdk 17.0.8
• Screen resolution: 1920x1200

[github-actions[bot]]

Thank you for your reporting your first LITIENGINE issue! We are looking forward to your further contributions.

[Hades948]

Looks like you're using jdk 17, which uses class version 61. Litiengine 0.8.0 was built on jdk 21, which uses class version 65. You probably just need to be using jdk 21.

[poach3r]

The docs say that JDK 17 is the lowest version which works, "Since LITIENGINE has been created with Java 17, you need at least JDK 17 on your machine.", I will install JDK 21 and report back.

[Hades948]

Oh, gotcha. It used to be 17, so we probably missed updating the documentation. Can you provide a link to where you found that? Then we can probably keep this issue open as a doc issue.

[poach3r]

I've tried it again with Adoptium 21 and it fixed the issue, I found the error in question at https://litiengine.com/docs/getting-started/install-jdk/

[nightm4re94]

Thank you for reporting and sorry for the outdated documentation. We'll fix this ASAP.

[nightm4re94]

@Hades948 has updated the docs. Thank you!