Unsupported value type "${typeof value}" at row ${rowIndex},

Error message

Unsupported value type "${typeof value}" at row ${rowIndex}, column ${colIndex}

What it means

Error "Unsupported value type "${typeof value}" at row ${rowIndex}, column ${colIndex}" thrown in n8n-io/n8n.

Source

Thrown at packages/@n8n/instance-ai/src/parsers/structured-file-parser.ts:256

// ── Parsing core ────────────────────────────────────────────────────────────

function validateCellValue(value: unknown, colIndex: number, rowIndex: number): CellValue {
	if (value === null || value === undefined || value === '') return null;
	if (typeof value === 'boolean') return value;
	if (typeof value === 'number') {
		if (!isFinite(value)) return null;
		return value;
	}
	if (typeof value === 'string') {
		if (value.length > MAX_CELL_STRING_LENGTH) {
			throw new Error(
				`Cell at row ${rowIndex}, column ${colIndex} exceeds max string length of ${MAX_CELL_STRING_LENGTH} characters`,
			);
		}
		return value;
	}
	// Arrays and objects are not allowed in flat rows
	throw new Error(
		`Unsupported value type "${typeof value}" at row ${rowIndex}, column ${colIndex}`,
	);
}

function hasDangerousKey(obj: Record<string, unknown>): string | undefined {
	for (const key of Object.keys(obj)) {
		if (DANGEROUS_KEYS.has(key)) return key;
	}
	return undefined;
}

function parseCsvTsv(
	content: string,
	format: 'csv' | 'tsv',
	options: { hasHeader: boolean; delimiter?: string },
): { rawHeaders: string[]; allRows: string[][] } {
	const delimiter = options.delimiter ?? (format === 'tsv' ? '\t' : ',');

View on GitHub (pinned to 5ac6606e81)

When it happens

Trigger: Thrown at packages/@n8n/instance-ai/src/parsers/structured-file-parser.ts:256 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of n8n-io/n8n@5ac6606e81 (2026-08-12). Data as JSON: /api/errors/01b33486531f141f. Report an issue: GitHub.