n8n-io/n8n · error

Failed to write ${label.toLowerCase()} "${filePath}": ${form

Error message

Failed to write ${label.toLowerCase()} "${filePath}": ${formatErrorForLog(error)}; command fallback failed: ${formatErrorForLog(fallbackError)}

What it means

Thrown by writeWorkspaceFile when BOTH write paths fail: the primary workspace.filesystem.writeFile raised an error AND the sandbox command fallback (writeFileViaSandbox) also raised fallbackError. Neither was an abort error. The `cause` is chosen by selectWriteFailureCause, which prefers whichever of the two errors carries quota-exhausted metadata (errorCode === 'quota_exhausted') so callers can classify credit exhaustion correctly; otherwise the original write error wins.

Source

Thrown at packages/@n8n/instance-ai/src/workspace/workspace-files.ts:150

					}),
				filePath,
				options,
			);
			return;
		} catch (error) {
			if (isAbortError(error)) throw error;
			try {
				await writeFileViaSandbox(workspace, filePath, content, options);
				options?.logger.warn(`${label} filesystem write failed; used command fallback`, {
					path: filePath,
					error: formatErrorForLog(error),
				});
				return;
			} catch (fallbackError) {
				if (isAbortError(fallbackError)) throw fallbackError;
				// Preserve whichever path carries quota metadata so callers can
				// classify the combined failure correctly.
				throw new Error(
					`Failed to write ${label.toLowerCase()} "${filePath}": ${formatErrorForLog(error)}; command fallback failed: ${formatErrorForLog(fallbackError)}`,
					{ cause: selectWriteFailureCause(error, fallbackError) },
				);
			}
		}
	}

	try {
		await writeFileViaSandbox(workspace, filePath, content, options);
	} catch (error) {
		if (isAbortError(error)) throw error;
		throw new Error(
			`Failed to write ${label.toLowerCase()} "${filePath}": ${formatErrorForLog(error)}`,
			{ cause: error },
		);
	}
}

View on GitHub (pinned to 5ac6606e81)

Solutions

1. Inspect err.cause with isQuotaExhaustedError(cause) — if true, surface an Instance AI credits-exhausted message and stop retrying; writes will keep failing until credits refresh.
2. Check workspace disk usage with a sandbox command (df -h) if quota is not the cause.
3. Retry only if neither cause is quota_exhausted and the failure shape looks transient (status 5xx).
4. Verify the workspace is not paused/hibernated before writing.

Example fix

// before
await writeWorkspaceFile(workspace, filePath, content, opts);

// after — classify the combined failure
try {
  await writeWorkspaceFile(workspace, filePath, content, opts);
} catch (err) {
  if (isQuotaExhaustedError(err.cause)) {
    throw new Error('Instance AI credits exhausted — write blocked until credits refresh.');
  }
  throw err;
}

import { isQuotaExhaustedError } from './utils/quota-error';

function isQuotaWriteFailure(error: unknown): boolean {
  return error instanceof Error && isQuotaExhaustedError(error.cause);
}

try {
  await writeWorkspaceFile(workspace, filePath, content, opts);
} catch (err) {
  if (isQuotaWriteFailure(err)) {
    // surface credits-exhausted; do not retry
  } else {
    throw err;
  }
}

When it happens

Trigger: Calling writeWorkspaceFile where workspace.filesystem is defined (so the primary path runs) and both (a) filesystem.writeFile throws a non-abort error, and (b) writeFileViaSandbox throws a non-abort fallbackError inside the catch's try. Most common when the underlying resource (disk quota, Instance AI credit pool, or sandbox provider) is exhausted on both paths.

Common situations: Instance AI credit pool exhausted (quota_exhausted) — both the filesystem API and the command path report it; workspace disk full in Daytona so neither the API write nor the base64 command write can land; sandbox provider outage causing both the API and shell command to fail transiently at once.

Related errors

• Failed to write ${label.toLowerCase()} "${filePath}": ${form
• Duplicate skill source directory "${normalizedSkill.sourceDi
• Invalid skill at ${sourceDirectory}: ${errors.join('; ')}
• Filesystem "${this.id}" is not ready (status: ${this.status}
• File not found: ${path}

AI-assisted analysis of n8n-io/n8n@5ac6606e81 (2026-08-12). Data as JSON: /api/errors/b8b2f5ae0853f972. Report an issue: GitHub.