n8n-io/n8n · error · NodeOperationError

Auto-fixing parser prompt has to contain {error} placeholder

Error message

Auto-fixing parser prompt has to contain {error} placeholder

What it means

Error "Auto-fixing parser prompt has to contain {error} placeholder" thrown in n8n-io/n8n.

Source

Thrown at packages/@n8n/nodes-langchain/nodes/output_parser/OutputParserStructured/OutputParserStructured.node.ts:251

				'Error during parsing of JSON Schema. Please check the schema and try again.',
			);
		}

		if (!autoFix) {
			return {
				response: outputParser,
			};
		}

		const model = (await this.getInputConnectionData(
			NodeConnectionTypes.AiLanguageModel,
			itemIndex,
		)) as BaseLanguageModel;

		const prompt = this.getNodeParameter('prompt', itemIndex, NAIVE_FIX_PROMPT) as string;

		if (prompt.length === 0 || !prompt.includes('{error}')) {
			throw new NodeOperationError(
				this.getNode(),
				'Auto-fixing parser prompt has to contain {error} placeholder',
			);
		}
		const parser = new N8nOutputFixingParser(
			this,
			model,
			outputParser,
			PromptTemplate.fromTemplate(prompt),
		);

		return {
			response: parser,
		};
	}
}

View on GitHub (pinned to 5ac6606e81)

When it happens

Trigger: Thrown at packages/@n8n/nodes-langchain/nodes/output_parser/OutputParserStructured/OutputParserStructured.node.ts:251 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/286ad25a87e2915f. Report an issue: GitHub.