What causes "Invalid LUT color on line ${index + 1}." in remotion-dev/remotion?

Fix the reported line to contain exactly three whitespace-separated finite decimal numbers.

Invalid LUT color on line

Error message

Invalid LUT color on line ${index + 1}.

What it means

Every data line in a .cube file must be exactly three finite numbers (r g b). parseCubeLut builds a color from the first token plus the remaining tokens and throws this error when the line does not yield exactly 3 values, or any value is not finite after Math.fround (NaN, Infinity, or non-numeric tokens). The 1-based line number is included so the broken row can be located quickly.

Solutions

Fix the reported line to contain exactly three whitespace-separated finite decimal numbers.
Replace comma decimal separators with dots and remove any thousands separators.
Delete extra columns (e.g. alpha or index) so only r g b remain.
Re-export the LUT from the source application.
Pre-validate each data line with a regex like /^[\d.eE+-.]+\s+[\d.eE+-.]+\s+[\d.eE+-.]+$/ before calling parseCubeLut.

Example fix

// before (comma decimals)
0,5 0,5 0,5
// after
0.5 0.5 0.5

Defensive patterns

Strategy: validation

Validate before calling

const isColorLine = (line: string): boolean => {
  const parts = line.trim().split(/\s+/);
  return parts.length === 3 && parts.every((p) => Number.isFinite(Number(p)));
};

Try / catch

try {
  const lut = parseCubeLut(text);
} catch (e) {
  const m = /line (\d+)/.exec((e as Error).message);
  if (m) console.error(`Bad color row at line ${m[1]}`);
}

Prevention

Use dots, not commas, as decimal separators in .cube data
Keep exactly three whitespace-separated columns per data line
Re-export rather than hand-editing color tables

When it happens

Trigger: parseCubeLut(text) with a data line like '0.5 0.5' (two values), 'r g b' (non-numeric tokens that slipped past the header regex, e.g. lowercase), '1 2 3 4' (four values), or containing NaN/Infinity values.

Common situations: CSV-exported data pasted into .cube files; files with tab/comma separators where split(/\s+/) still works but one field is empty; locale-formatted numbers ('0,5 0,5 0,5') that Number() turns into NaN; extra alpha channel column.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

AI-assisted analysis of remotion-dev/remotion@46a3a6bf13 (2026-09-18). Data as JSON: /api/errors/c4e98b08657e071c. Report an issue: GitHub.

Appendix: source

Thrown at packages/studio/src/helpers/cube-lut.ts:114

			continue;
		}

		if (isHeader) {
			throw new Error(
				`Unsupported LUT header "${keyword}" on line ${index + 1}.`,
			);
		}

		if (data === null) {
			throw new Error('Expected LUT_1D_SIZE or LUT_3D_SIZE before color data.');
		}

		const color = [Number(keyword), ...numbers];
		if (
			color.length !== 3 ||
			!color.every((value) => Number.isFinite(Math.fround(value)))
		) {
			throw new Error(`Invalid LUT color on line ${index + 1}.`);
		}

		if (offset + 3 > data.length) {
			throw new Error(`Expected ${data.length / 3} LUT colors, got more.`);
		}

		data.set(color, offset);
		offset += 3;
	}

	if (type === null || data === null) {
		throw new Error('Expected LUT_1D_SIZE or LUT_3D_SIZE.');
	}

	if (offset !== data.length) {
		throw new Error(
			`Expected ${data.length / 3} LUT colors, got ${offset / 3}.`,
		);

View on GitHub (pinned to 46a3a6bf13)