remotion-dev/remotion · critical · Error

Flannel shader compile failed: ${log ?? '(no log)'}

Error message

Flannel shader compile failed: ${log ?? '(no log)'}

What it means

Thrown when the flannel GLSL fragment/vertex shader fails to compile. The error appends the GPU's info log, which pinpoints the offending line. This indicates a bug in the bundled shader source, a GLSL feature unsupported by the device, or a corrupted shader string.

Source

Thrown at packages/effects/src/flannel.ts:202

}
`;

const compileShader = (
	gl: WebGL2RenderingContext,
	type: number,
	source: string,
): WebGLShader => {
	const shader = gl.createShader(type);
	if (!shader) {
		throw new Error('Failed to create WebGL shader');
	}

	gl.shaderSource(shader, source);
	gl.compileShader(shader);
	if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
		const log = gl.getShaderInfoLog(shader);
		gl.deleteShader(shader);
		throw new Error(`Flannel shader compile failed: ${log ?? '(no log)'}`);
	}

	return shader;
};

const setupFlannel = (target: HTMLCanvasElement): FlannelState => {
	const gl = target.getContext('webgl2', {
		premultipliedAlpha: true,
		alpha: true,
		preserveDrawingBuffer: true,
	});
	if (!gl) {
		throw createWebGL2ContextError('flannel effect');
	}

	gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, true);
	const vertexShader = compileShader(gl, gl.VERTEX_SHADER, FLANNEL_VS);
	const fragmentShader = compileShader(gl, gl.FRAGMENT_SHADER, FLANNEL_FS);

View on GitHub (pinned to 78fe4bb3fd)

Solutions

1. Read the appended info log to find the offending GLSL line.
2. Report the issue with the full log and Chrome/GPU info to the Remotion maintainers if using a released version.
3. Reproduce in Remotion Studio locally to confirm whether it is environment-specific.

try {
  effect = flannel(params);
} catch (err) {
  if (/shader compile failed/i.test(String(err))) {
    console.error('Flannel shader compile failure; report log:', String(err));
  }
  throw err;
}

When it happens

Trigger: A bug in the shipped FLANNEL_VS/FLANNEL_FS source (regression after editing); a device/driver that rejects a GLSL ES 3.00 construct used by the shader; the shader string was inadvertently truncated.

Common situations: Developing the flannel shader and introducing a syntax error; running on an older GPU whose GLSL ES 300 support is partial; an extension was disabled that the shader relies on.

Related errors

• Flannel program link failed: ${log ?? '(no log)'}
• Glow shader compile failed: ${log ?? '(no log)'}
• Shader compile failed: ${log ?? '(no log)'}
• Burlap shader compile failed: ${log ?? '(no log)'}
• Failed to create WebGL shader

AI-assisted analysis of remotion-dev/remotion@78fe4bb3fd (2026-08-12). Data as JSON: /api/errors/7b2127bf52a6c761. Report an issue: GitHub.