Encountered an issue when using LwjglCanvas in version 3.10.0-alpha1

[foxcc2021]

This issue occurs in 3.10.0-alpha1, but it works fine in version 3.9.0-stable.

Feb 11, 2026 9:55:27 PM com.jme3.system.JmeDesktopSystem initialize
INFO: Running on jMonkeyEngine 3.10.0-alpha1

• Branch: HEAD
• Git Hash: d3efabc
• Build Date: 2026-02-09
  Feb 11, 2026 9:55:28 PM com.jme3.system.lwjgl.LwjglContext printContextInitInfo
  INFO: LWJGL 3.4.0+20 context running on thread jME3 Main
• Graphics Adapter: GLFW 3.5.0 Win32 WGL Null EGL OSMesa VisualC DLL
  Feb 11, 2026 9:55:28 PM com.jme3.system.lwjgl.LwjglCanvas printContextInitInfo
  INFO: Initializing LWJGL3-AWT with jMonkeyEngine
• Double Buffer: true
• Stereo: false
• Red Size: 8
• Green Size: 8
• Blue Size: 8
• Alpha Size: 0
• Depth Size: 24
• Stencil Size: 0
• Accum Red Size: 0
• Accum Green Size: 0
• Accum Blue Size: 0
• Accum Alpha Size: 0
• Sample Buffers: 0
• Share Context: null
• Major Version: 3
• Minor Version: 2
• Forward Compatible: false
• Profile: COMPATIBILITY
• API: GL
• Debug: false
• Swap Interval: 1
• SRGB (Gamma Correction): true
• Pixel Format Float: false
• Context Release Behavior: null
• Color Samples NV: 0
• Swap Group NV: 0
• Swap Barrier NV: 0
• Robustness: false
• Lose Context On Reset: false
• Context Reset Isolation: false
  Feb 11, 2026 9:55:28 PM com.jme3.renderer.opengl.GLRenderer loadCapabilitiesCommon
  INFO: OpenGL Renderer Information
• Vendor: NVIDIA Corporation
• Renderer: NVIDIA GeForce RTX 3060/PCIe/SSE2
• OpenGL Version: 3.2.0 NVIDIA 560.94
• GLSL Version: 1.50 NVIDIA via Cg compiler
• Profile: Core
  Feb 11, 2026 9:55:28 PM com.jme3.audio.openal.ALAudioRenderer printAudioRendererInfo
  INFO: Audio Renderer Information
• Device: OpenAL Soft
• Vendor: OpenAL Community
• Renderer: OpenAL Soft
• Version: 1.1 ALSOFT 1.25.0
• Supported channels: 64
• ALC extensions: ALC_ENUMERATE_ALL_EXT ALC_ENUMERATION_EXT ALC_EXT_CAPTURE ALC_EXT_debug ALC_EXT_DEDICATED ALC_EXT_direct_context ALC_EXT_disconnect ALC_EXT_EFX ALC_EXT_thread_local_context ALC_SOFT_device_clock ALC_SOFT_HRTF ALC_SOFT_loopback ALC_SOFT_loopback_bformat ALC_SOFT_output_limiter ALC_SOFT_output_mode ALC_SOFT_pause_device ALC_SOFT_reopen_device ALC_SOFT_system_events
• AL extensions: AL_EXT_ALAW AL_EXT_BFORMAT AL_EXT_debug AL_EXT_direct_context AL_EXT_DOUBLE AL_EXT_EXPONENT_DISTANCE AL_EXT_FLOAT32 AL_EXT_IMA4 AL_EXT_LINEAR_DISTANCE AL_EXT_MCFORMATS AL_EXT_MULAW AL_EXT_MULAW_BFORMAT AL_EXT_MULAW_MCFORMATS AL_EXT_OFFSET AL_EXT_source_distance_model AL_EXT_SOURCE_RADIUS AL_EXT_STATIC_BUFFER AL_EXT_STEREO_ANGLES AL_LOKI_quadriphonic AL_SOFT_bformat_ex AL_SOFT_bformat_hoa AL_SOFT_block_alignment AL_SOFT_buffer_length_query AL_SOFT_callback_buffer AL_SOFTX_convolution_effect AL_SOFT_deferred_updates AL_SOFT_direct_channels AL_SOFT_direct_channels_remix AL_SOFT_effect_target AL_SOFT_events AL_SOFT_gain_clamp_ex AL_SOFTX_hold_on_disconnect AL_SOFT_loop_points AL_SOFTX_map_buffer AL_SOFT_MSADPCM AL_SOFT_source_latency AL_SOFT_source_length AL_SOFTX_source_panning AL_SOFT_source_resampler AL_SOFT_source_spatialize AL_SOFT_source_start_delay AL_SOFT_UHJ AL_SOFT_UHJ_ex
  Feb 11, 2026 9:55:28 PM com.jme3.audio.openal.ALAudioRenderer initEfx
  INFO: Audio effect extension version: 1.0
  Feb 11, 2026 9:55:28 PM com.jme3.audio.openal.ALAudioRenderer initEfx
  INFO: Audio max auxiliary sends: 2
  Feb 11, 2026 9:55:29 PM com.jme3.app.LegacyApplication handleError
  SEVERE: Uncaught exception thrown in Thread[Proper context cleanup on crash #30,jME3 Main,5,main]
  java.lang.NoSuchMethodError: 'org.lwjgl.system.windows.PIXELFORMATDESCRIPTOR org.lwjgl.system.windows.PIXELFORMATDESCRIPTOR.callocStack(org.lwjgl.system.MemoryStack)'
  at org.lwjgl.opengl.awt.PlatformWin32GLCanvas.create(PlatformWin32GLCanvas.java:184)
  at org.lwjgl.opengl.awt.PlatformWin32GLCanvas.create(PlatformWin32GLCanvas.java:156)
  at com.jme3.system.lwjgl.LwjglCanvas$LwjglAWTGLCanvas.beforeRender(LwjglCanvas.java:248)
  at com.jme3.system.lwjgl.LwjglCanvas.runLoop(LwjglCanvas.java:623)
  at com.jme3.system.lwjgl.LwjglWindow.run(LwjglWindow.java:819)
  at java.base/java.lang.Thread.run(Thread.java:1583)

Feb 11, 2026 9:55:29 PM com.jme3.system.JmeSystemDelegate lambda$new$0
WARNING: JmeDialogsFactory implementation not found.
Uncaught exception thrown in Thread[#30,jME3 Main,5,main]
NoSuchMethodError: 'org.lwjgl.system.windows.PIXELFORMATDESCRIPTOR org.lwjgl.system.windows.PIXELFORMATDESCRIPTOR.callocStack(org.lwjgl.system.MemoryStack)'
Feb 11, 2026 9:55:29 PM com.jme3.audio.openal.ALAudioRenderer destroyOpenAL
INFO: OpenAL context destroyed.

[yaRnMcDonuts]

3.10.0-alpha1 upgrades LWJGL to the newer LWJGL3.4.0 version that comes with many internal changes, so this is likely the cause of this issue.

I did quickly try this code that creates a LwjglCanvas with a JmeDialogsFactoryImpl on 3.10.0.alpha1, however I did not encounter the exception.

        AppSettings settings = new AppSettings(true);

        JmeDialogsFactory dialogsFactory = new JmeDialogsFactoryImpl();

        dialogsFactory.showSettingsDialog(settings, true);
        app.setSettings(settings);

        LwjglCanvas canvas = new LwjglCanvas();
        JFrame frame = new JFrame("jME Canvas + Dialogs Test");
        frame.setSize(settings.getWidth(), settings.getHeight());
        frame.add(canvas.getCanvas());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);

        canvas.create(true);
        dialogsFactory.showErrorDialog("Test");

The exception is most likely due to a version mismatch in your environment, so I'd first recommend double checking that you are using the new 3.10.0 -alpha1 version of the jme3-LWJGL3 module. And if it still occurs, then I'd suggest creating a minimal test case to reproduce the issue. (or if you are having this problem in the jme SDK, you may be encountering an unavoidable version-mismatch until the SDK is updated to have a 3.10 release)

[JNightRider]

It appears this error only occurs on Windows. After investigating the internal changes in lwjgl3-v4.0.x, I discovered that deprecated methods were removed (as @yaRnMcDonuts mentions), causing an error when calling the callocStack(...) method of the native class PIXELFORMATDESCRIPTOR.

I opened an issue requesting a release for this patch in the lwjgx-awt repository; updating the library would resolve this issue.

[yaRnMcDonuts]

I am running windows as well but I'm still struggling to reproduce the method not found error.

I believe callocStack gets called internally with my previous test, however, to be sure the method exists, I've also made this test to directly call that method:

import com.jme3.app.SimpleApplication;
import org.lwjgl.system.MemoryStack;
import org.lwjgl.system.windows.PIXELFORMATDESCRIPTOR;

public class MethodNotFoundTest extends SimpleApplication{
    public static void main(String[] args) {

        MethodNotFoundTest m = new MethodNotFoundTest();        
        m.start();

    }

    @Override
    public void simpleInitApp() {
        
        getContext().setSystemListener(this);
        
        try (MemoryStack stack = MemoryStack.stackPush()) {
            PIXELFORMATDESCRIPTOR.calloc(stack);
            System.out.println("CallocStack called sucesfully");
        }
        catch(Exception e){
            e.printStackTrace();
        }
        
    }
}

And it looks like it runs on my Windows 10 device with no exception and sucessfuly prints out "CallocStack called sucesfully" in the console.

Can you try this test case in a new project using all of the 3.10.0-alpha jars/implementation and see if the method not found exception still occurs?

Here is a screenshot verifying it is indeed running on my windows device while using 3.10.0-alpha1.

And here is the gradle build file to ensure I'm using LWJGL3 with the same $jmever param for all engine dependencies (as to avoid a version mismatch that may cause issues if you try using the 3.9 jme3-lwlgl3 or 3.9 jme3-awt-dialogs dependency with any newer 3.10.0alpha1 dependencies or anything like that)

Or am I overlooking something?

[yaRnMcDonuts]

So I just realized you are using the external lwjgl-dialogs library (which still hasn't updated the method to coincide with the LWJGL 3.4.0 changes yet.

Is there any reason you are not just using the jme3-awt-dialogs module included in our jmonkey repo? Since that seems to work out-of-the-box with jME and is far less likely to cause version mismatches when used with jME.

[JNightRider]

I believe callocStack gets called internally with my previous test, however, to be sure the method exists, I've also made this test to directly call that method:

The method calloc(stack); does exist, but callocStack(stack) does not exist in version 4.x of lwjgl3, that is:

Can you try this test case in a new project using all of the 3.10.0-alpha jars/implementation and see if the method not found exception still occurs?

1. works fine (lwjgl3 v3.4.x)

try (MemoryStack stack = MemoryStack.stackGet()) {
    PIXELFORMATDESCRIPTOR pixelformatdescriptor = PIXELFORMATDESCRIPTOR.calloc(stack)
}

2. It throws an exception because the method does not exist (lwjgl3 v3.4.x)

try (MemoryStack stack = MemoryStack.stackGet()) {
    PIXELFORMATDESCRIPTOR pixelformatdescriptor = PIXELFORMATDESCRIPTOR.callocStack(stack)
}

This method existed in version 3.3.x, but was removed in version 3.4.x, therefore it interferes with the creation of the gl context in Windows.

lwjglx-awt has been updated to version 3.4.0, but they haven't released a public version, as jme3 currently uses version 0.2.3 of lwjglx-awt, which uses the deprecated method mentioned above (see here).

I performed further tests in a controlled manner, and these are the results:

[ with JME3 v3.10.0-alpha1 | Windows 11 ]

It always fails...

[ with JME3 v3.9.0-stable | Windows 11 ]

It works, because there is compatibility.

1. Code

import com.jme3.app.SimpleApplication;
import com.jme3.material.Material;
import com.jme3.math.ColorRGBA;
import com.jme3.scene.Geometry;
import com.jme3.scene.shape.Box;
import com.jme3.system.JmeCanvasContext;

import javax.swing.*;
import java.awt.*;

public class Egawt extends SimpleApplication {

    public static void main(String[] args) {
        Egawt app = new Egawt();
        app.setShowSettings(false);
        app.createCanvas();
        app.startCanvas();

        Dimension size = new Dimension(1024, 576);

        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setPreferredSize(size);

        JmeCanvasContext context = (JmeCanvasContext) app.getContext();
        Canvas canvas = context.getCanvas();
        canvas.setPreferredSize(size);

        frame.getContentPane().add(context.getCanvas());
        frame.pack();

        frame.setVisible(true);
    }

    @Override
    public void simpleInitApp() {
        getFlyByCamera().setDragToRotate(true);

        Box b = new Box(1, 1, 1);
        Geometry geom = new Geometry("Box", b);

        Material mat = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
        mat.setColor("Color", ColorRGBA.Blue);
        geom.setMaterial(mat);

        rootNode.attachChild(geom);
    }
}

2. Gradle

plugins {
    id 'application'
    id 'java'
}

description = 'Egawt application'

java {
    sourceCompatibility = '17'
    targetCompatibility = '17'
}

ext.jmonkeyengineVersion = '3.10.0-alpha1'

mainClassName = 'e.g.awt.Egawt'
if (!hasProperty('mainClass')) {
    ext.mainClass = mainClassName
}
jar.manifest.attributes('Main-Class': mainClassName)

repositories {
    mavenCentral()
    mavenLocal()
}

application {
    if (System.getProperty("os.name").toLowerCase().contains("mac")) {
        applicationDefaultJvmArgs = ['-XstartOnFirstThread'] // this is when using a Mac as a development machine which requires the AppKit main UI thread to be used for GUI applications
    }
}

dependencies {
    implementation 'org.jmonkeyengine:jme3-core:' + jmonkeyengineVersion
    implementation 'org.jmonkeyengine:jme3-desktop:' + jmonkeyengineVersion
    runtimeOnly 'org.jmonkeyengine:jme3-jogg:' + jmonkeyengineVersion
    runtimeOnly 'org.jmonkeyengine:jme3-plugins:' + jmonkeyengineVersion


    runtimeOnly 'org.jmonkeyengine:jme3-lwjgl3:' + jmonkeyengineVersion
}

Is there any reason you are not just using the jme3-awt-dialogs module included in our jmonkey repo? Since that seems to work out-of-the-box with jME and is far less likely to cause version mismatches when used with jME.

I'm not entirely sure about this, but if I'm not mistaken, the jme3-awt-dialogs module only contains the startup (settings) window and the dialog box that jme3 launches during its execution (correct me if I'm wrong), so it wouldn't have any effect.

In theory, this error would be resolved by updating the lwjglx-awt library (lwjglx-awt has not yet released a version with this patch on Maven)

---

@yaRnMcDonuts Could you run another test with the code I provided? (to confirm the situation - I don't have a machine with Windows 10, only 11.)

[yaRnMcDonuts]

Thank you for the test case, now I do see the NoSuchMethodError when I run your code:

java.lang.NoSuchMethodError: 'org.lwjgl.system.windows.PIXELFORMATDESCRIPTOR org.lwjgl.system.windows.PIXELFORMATDESCRIPTOR.callocStack(org.lwjgl.system.MemoryStack)'
	at org.lwjgl.opengl.awt.PlatformWin32GLCanvas.create(PlatformWin32GLCanvas.java:184)
	at org.lwjgl.opengl.awt.PlatformWin32GLCanvas.create(PlatformWin32GLCanvas.java:156)
	at com.jme3.system.lwjgl.LwjglCanvas$LwjglAWTGLCanvas.beforeRender(LwjglCanvas.java:248)
	at com.jme3.system.lwjgl.LwjglCanvas.runLoop(LwjglCanvas.java:623)
	at com.jme3.system.lwjgl.LwjglWindow.run(LwjglWindow.java:819)
	at java.base/java.lang.Thread.run(Thread.java:1583)

My original test case that created a DialogsFactory and a Canvas appears to have been too simplified and must have never triggered the internal call to the method that causes the exception. (I admittedly have very little experience using awt with lwjgl so I appreciate you making the test case that does reproduce this)

Now that we have the exception, we can work on a PR to fix it in the jme3-awt-dialog code.

I'm not entirely sure about this, but if I'm not mistaken, the jme3-awt-dialogs module only contains the startup (settings) window and the dialog box that jme3 launches during its execution (correct me if I'm wrong), so it wouldn't have any effect.

I personally don't use awt with lwjgl so I'm not entirely certain either (most of my knowledge on the library comes from my investigation into this issue today). My understanding (which could be wrong) was that both libraries are mostly just a wrapper to put awt components in a LWJGLCanvas in which case I'd expect the jme implementation would work for most use cases, unless there's extra feaures/magic that the lwjglx awt library is providing that I've overlooked (but I only briefly looked at that library so I would take my suggestion with a grain of salt. I suppose the best way to know is to try jME's implementation and see if it provides what you need for your use case, or if its missing something important that you need. If the jME implementation is only lightly lacking in features it could be worth adding onto, but if its severely lacking then you may be best off using the other one).

[foxcc2021]

I apologize, I thought this issue was relatively easy to trigger, so I only briefly posted the error log.

I'm using Windows 11 and OpenJDK 21.0.8. Below is the code I used for testing:

import com.jme3.app.LegacyApplication;
import com.jme3.app.SimpleApplication;
import com.jme3.app.StatsAppState;
import com.jme3.scene.Geometry;
import com.jme3.scene.shape.Box;
import com.jme3.system.AppSettings;
import com.jme3.system.JmeCanvasContext;
import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Container;
import java.awt.Dimension;
import java.lang.reflect.InvocationTargetException;
import java.util.concurrent.Callable;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import se.core.utils.MaterialUtils;

/**
 *
 * @author foxcc
 */
public class TestCanvas extends SimpleApplication {
    
    private static JmeCanvasContext context;
    private static Canvas canvas;
    private static JFrame frame;
    private static Container canvasPanel1;
    private static LegacyApplication app;

    private static void createFrame(){
        frame = new JFrame("Test");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        canvasPanel1 = new JPanel();
        canvasPanel1.setLayout(new BorderLayout());
        frame.setContentPane(canvasPanel1);
    }

    @SuppressWarnings("unchecked")
    public static void createCanvas(String appClass){
        AppSettings settings = new AppSettings(true);
        settings.setWidth(1280);
        settings.setHeight(720);

        try{
            Class clazz = Class.forName(appClass);
            app = (LegacyApplication) clazz.getDeclaredConstructor().newInstance();
        }catch (ClassNotFoundException
                | InstantiationException
                | IllegalAccessException
                | IllegalArgumentException
                | InvocationTargetException
                | NoSuchMethodException
                | SecurityException ex) {
            ex.printStackTrace();
        }

        app.setPauseOnLostFocus(false);
        app.setSettings(settings);
        app.createCanvas();
        app.startCanvas();
        
        context = (JmeCanvasContext) app.getContext();
        canvas = context.getCanvas();
        canvas.setPreferredSize(new Dimension(1280, 720));
        
    }

    public static void startApp(){
        app.startCanvas();
        app.enqueue(new Callable<Void>(){
            @Override
            public Void call(){
                if (app instanceof SimpleApplication){
                    SimpleApplication simpleApp = (SimpleApplication) app;
                    simpleApp.getFlyByCamera().setDragToRotate(true);
                }
                return null;
            }
        });
    }

    public static void main(String[] args){
        createCanvas(TestCanvas.class.getName());

        try {
            Thread.sleep(500);
        } catch (InterruptedException ex) {
        }

        SwingUtilities.invokeLater(new Runnable(){
            @Override
            public void run(){
                createFrame();
                canvasPanel1.add(canvas, BorderLayout.CENTER);
                
                frame.pack();
                startApp();
                frame.setTitle("Testing");
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    @Override
    public void simpleInitApp() {
        this.stateManager.attach(new StatsAppState());
        Geometry geo = new Geometry("test", new Box(1,1,1));
        geo.setMaterial(MaterialUtils.createUnshadedMaterial(assetManager));
        rootNode.attachChild(geo);
    }
}```

[yaRnMcDonuts]

java.lang.NoSuchMethodError: 'org.lwjgl.system.windows.PIXELFORMATDESCRIPTOR org.lwjgl.system.windows.PIXELFORMATDESCRIPTOR.callocStack(org.lwjgl.system.MemoryStack)'
	at org.lwjgl.opengl.awt.PlatformWin32GLCanvas.create(PlatformWin32GLCanvas.java:184)
	at org.lwjgl.opengl.awt.PlatformWin32GLCanvas.create(PlatformWin32GLCanvas.java:156)
	at com.jme3.system.lwjgl.LwjglCanvas$LwjglAWTGLCanvas.beforeRender(LwjglCanvas.java:248)
	at com.jme3.system.lwjgl.LwjglCanvas.runLoop(LwjglCanvas.java:623)
	at com.jme3.system.lwjgl.LwjglWindow.run(LwjglWindow.java:819)
	at java.base/java.lang.Thread.run(Thread.java:1583)

Well now that I look at that exception and I dug deeper into our jme implementation, it looks like our jme3-awt-dialogs depends directly on the same lwjglx library that @JNightRider you submitted an issue to (my mistake for overlooking that from the get go, but now that I have been able to reproduce the exception everything is now making sense).

Since it sounds like they are having issues uploading to maven (and are waiting on someone who's been inactive to do so) then we may be best off building the jar and importing it directly into jME or forking the repo and including that, since it sounds like it may be a long time until its on maven.

But in the meantime, you can both at least fix the issue by building that jar from their master branch (which will likely be easier and faster than getting the fix into jME)

Thank you both for reporting the issue here and on the lwjglx awt repo. (and sorry for my lack of understanding in this area, as I've been figuring everything out on the fly. But at least we finally got to the bottom of this issue)

[stephengold]

LWJGLX/lwjgl3-awt@9883034

I think they're telling us to fork the lwjgl-awt repo and publish our own artifacts.

[JNightRider]

Although I'd like to be optimistic, everything indicates that this is the path LWJGLX will take...

A few days ago I started working on a version of this library to improve it and provide support for all functionalities so that it can integrate better with JME... I've made some progress, but AWT and GL still have a major flaw (freeing/destroying the context).

LWJGZ-JAWT - Although it's just a prototype

I believe the best option is for JME3 to release a version of this library to fix this minor issue.

[yaRnMcDonuts]

I believe the best option is for JME3 to release a version of this library to fix this minor issue.

I agree.

@riccardobl mentioned that he'd look into forking the repo and include it under the jMonkey github organization, and set it up to be deployed to Maven Central with sonatype's publisher portal the same way we do with new engine releases. @riccardobl do you have any updates on this plan?

[riccardobl]

@yaRnMcDonuts done: https://github.com/jMonkeyEngine/lwjgl3-awt
I forked the original lwjgl3-awt repo, converted the build to gradle, fixed the failing tests and triggered a new 0.2.4 release under our org in maven central org.jmonkeyengine/lwjgl3-awt.

@JNightRider feel free to submit any pr to this fork.

I personally have no experience in embedding jme in awt, so, not sure if those pending PRs on the original lwjgl3-awt repo apply to us, but if they do, we should consider merging them.