libgdx/libgdx · critical · GdxRuntimeException

Couldn't instantiate GLES20.

Error message

Couldn't instantiate GLES20.

What it means

Lwjgl3Graphics failed to instantiate the GLES20 emulation layer. When glEmulation is ANGLE, gdx reflectively loads com.badlogic.gdx.backends.lwjgl3.angle.Lwjgl3GLES20; any Throwable from Class.forName/newInstance (class missing because the angle backend module isn't on the classpath, static init failure, linkage error) is wrapped in this GdxRuntimeException.

Source

Thrown at backends/gdx-backend-lwjgl3/src/com/badlogic/gdx/backends/lwjgl3/Lwjgl3Graphics.java:106

				window.asyncResized = true;
			}
		}
	};

	public Lwjgl3Graphics (Lwjgl3Window window) {
		this.window = window;
		if (window.getConfig().glEmulation == Lwjgl3ApplicationConfiguration.GLEmulation.GL32) {
			this.gl20 = this.gl30 = this.gl31 = this.gl32 = new Lwjgl3GL32();
		} else if (window.getConfig().glEmulation == Lwjgl3ApplicationConfiguration.GLEmulation.GL31) {
			this.gl20 = this.gl30 = this.gl31 = new Lwjgl3GL31();
		} else if (window.getConfig().glEmulation == Lwjgl3ApplicationConfiguration.GLEmulation.GL30) {
			this.gl20 = this.gl30 = new Lwjgl3GL30();
		} else {
			try {
				this.gl20 = window.getConfig().glEmulation == Lwjgl3ApplicationConfiguration.GLEmulation.GL20 ? new Lwjgl3GL20()
					: (GL20)Class.forName("com.badlogic.gdx.backends.lwjgl3.angle.Lwjgl3GLES20").newInstance();
			} catch (Throwable t) {
				throw new GdxRuntimeException("Couldn't instantiate GLES20.", t);
			}
			this.gl30 = null;
		}
		updateFramebufferInfo();
		initiateGL();
		GLFW.glfwSetFramebufferSizeCallback(window.getWindowHandle(), resizeCallback);
	}

	private void initiateGL () {
		String versionString = gl20.glGetString(GL11.GL_VERSION);
		String vendorString = gl20.glGetString(GL11.GL_VENDOR);
		String rendererString = gl20.glGetString(GL11.GL_RENDERER);
		glVersion = new GLVersion(Application.ApplicationType.Desktop, versionString, vendorString, rendererString);
		if (supportsCubeMapSeamless()) {
			enableCubeMapSeamless(true);
		}
	}

View on GitHub (pinned to 97f4086187)

Solutions

1. Add the matching libGDX ANGLE/GLES backend dependency with the same version as gdx-backend-lwjgl3 (e.g. gdx-backend-lwjgl3-angle / the angle natives packaging).
2. If you don't need GLES emulation, leave glEmulation at the default (GL20 or GL30) so Lwjgl3GL20 is used directly.
3. Inspect the cause in the stack trace (getCause()) — it names the real reason: ClassNotFoundException, NoClassDefFoundError, or init failure.
4. On module-path setups, ensure the angle package is readable (add-opens/requires as appropriate).

Example fix

// before
config.glEmulation = Lwjgl3ApplicationConfiguration.GLEmulation.ANGLE_GLES20; // class missing at runtime

// after (Gradle)
dependencies {
    implementation "com.badlogicgames.gdx:gdx-backend-lwjgl3:$gdxVersion"
    implementation "com.badlogicgames.gdx:gdx-backend-lwjgl3-angle:$gdxVersion" // same version
}

try {
    Class.forName("com.badlogic.gdx.backends.lwjgl3.angle.Lwjgl3GLES20", false, Lwjgl3Graphics.class.getClassLoader());
} catch (ClassNotFoundException e) {
    System.err.println("ANGLE/GLES backend not on classpath; falling back to GL20 emulation");
}

try {
    new Lwjgl3Application(listener, config);
} catch (GdxRuntimeException e) {
    if (e.getMessage() != null && e.getMessage().contains("GLES20")) {
        config.glEmulation = Lwjgl3ApplicationConfiguration.GLEmulation.GL20;
        new Lwjgl3Application(listener, config);
    } else throw e;
}

When it happens

Trigger: Configuring Lwjgl3ApplicationConfiguration.glEmulation = GLEmulation.ANGLE_GLES20 (or otherwise non-GL20/30/31/32) without shipping the gdx-backend-lwjgl3-angle (libGDX ANGLE/GLES) artifacts, or on a JVM/module path where that class cannot link.

Common situations: Running desktop with GLES20 emulation for parity with Android; Gradle project missing the angle backend dependency or version mismatch between gdx-backend-lwjgl3 and the angle module; JPMS setups that don't export the angle package; broken static initializer in the GLES20 class.

Related errors

• Couldn't load ANGLE.
• Couldn't initialize GLES
• Couldn't create window
• OpenGL 2.0 or higher with the FBO extension is required. Ope
• OpenGL 2.0 or higher with the FBO extension is required. Ope

AI-assisted analysis of libgdx/libgdx@97f4086187 (2026-08-14). Data as JSON: /api/errors/5944018d817e977b. Report an issue: GitHub.