remotion-dev/remotion · error · Error

customLayerArns must be specified when deploying to AWS Chin

Error message

customLayerArns must be specified when deploying to AWS China regions because Remotion-hosted Layers are not available in the aws-cn partition.

What it means

validateCustomLayerArns throws this during deployFunction when no customLayerArns were provided but the target region resolves to the aws-cn partition. Remotion-hosted layers exist only in the commercial `aws` partition, so a deployment to AWS China has no default layers to attach and the function would be unusable without explicitly supplied layer ARNs.

Source

Thrown at packages/lambda/src/shared/validate-custom-layer-arns.ts:24

const layerVersionArnRegex =
	/^arn:([a-z0-9][a-z0-9-]*):lambda:([a-z0-9-]+):(\d{12}):layer:([A-Za-z0-9-_]+):(\d+)$/;

export const validateCustomLayerArns = ({
	customLayerArns,
	enableLambdaInsights,
	region,
	runtimePreference,
}: {
	customLayerArns: string[] | null;
	enableLambdaInsights: boolean;
	region: AwsRegion;
	runtimePreference: RuntimePreference;
}) => {
	const {partition} = LambdaClientInternals.getAwsRegionMetadata(region);
	if (customLayerArns === null) {
		if (partition === 'aws-cn') {
			throw new Error(
				'customLayerArns must be specified when deploying to AWS China regions because Remotion-hosted Layers are not available in the aws-cn partition.',
			);
		}

		return;
	}

	if (!Array.isArray(customLayerArns) || customLayerArns.length === 0) {
		throw new TypeError('customLayerArns must contain at least one Layer ARN.');
	}

	if (runtimePreference !== 'default') {
		throw new Error(
			'customLayerArns cannot be combined with a non-default runtimePreference.',
		);
	}

	if (customLayerArns.length + (enableLambdaInsights ? 1 : 0) > 5) {

View on GitHub (pinned to 10db9de073)

Solutions

1. Copy the Remotion layer ZIPs (via `npx remotion lambda layers` in a supported region or the layer download URLs) into your China account, publish them as Lambda layers in cn-north-1/cn-northwest-1, and pass their version ARNs via `customLayerArns`.
2. Verify every supplied ARN starts with `arn:aws-cn:lambda:cn-...` so partition/region checks pass.
3. Keep runtimePreference at 'default' when supplying customLayerArns.

Example fix

// before
await deployFunction({region: 'cn-north-1', /* no customLayerArns */});

// after
await deployFunction({
  region: 'cn-north-1',
  runtimePreference: 'default',
  customLayerArns: [
    'arn:aws-cn:lambda:cn-north-1:123456789012:layer:remotion-chromium:1',
    'arn:aws-cn:lambda:cn-north-1:123456789012:layer:remotion-fonts:1',
  ],
});

const isChina = (region: string) => region.startsWith('cn-');
if (isChina(region) && (!customLayerArns || customLayerArns.length === 0)) {
  throw new Error('Build and pass customLayerArns for aws-cn before deploying');
}

When it happens

Trigger: Calling deployFunction (or `npx remotion lambda function deploy`) with region cn-north-1 / cn-northwest-1 and `customLayerArns: null` (or omitted).

Common situations: Companies with an AWS China account deploying Remotion Lambda for the first time; copy-pasting a deploy script from a global-region setup into a China-region pipeline.

Related errors

• Remotion-hosted Layers are not available in ${region}.
• Lambda functions support at most 5 Layers, including the Lam
• The custom Layer ARN ${layerArn} uses partition ${match[1]},
• customLayerArns must contain at least one Layer ARN.
• customLayerArns cannot be combined with a non-default runtim

AI-assisted analysis of remotion-dev/remotion@10db9de073 (2026-08-22). Data as JSON: /api/errors/5edd23e44086a2e4. Report an issue: GitHub.