Hi. I had that problem. I don't have an screenshot but I remember it was a problem with JavaFX. If I remember well, JavaFX was removed from the JRE. It means, it is not included by default and you should "install" it as separate dependency.
My advice to you is:
1- Create a VM and try to run your game there.
2- Write an instructions txt file with the steps you did for running the game.
Java is multiplatform but users may have different versions of the JRE, so you should write how to run it.
Look here the output when running the jar in the terminal:
(basically, it thows java.lang.ClassNotFoundException: com.sun.javafx.util.Utils)
arian@Arians-MacBook-Pro jar % java -jar Lizard_and_The_Magic_Doors.jar
Exception in thread "Thread-0" java.lang.NoClassDefFoundError: com/sun/javafx/util/Utils
at engine.Renderer.setPixel(Renderer.java:79)
at engine.Renderer.drawImage(Renderer.java:421)
at objects.Menu.render(Menu.java:75)
at game.GameManager.render(GameManager.java:87)
at engine.Engine.run(Engine.java:83)
at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: java.lang.ClassNotFoundException: com.sun.javafx.util.Utils
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
... 6 more
