n8n-io/n8n · error

EXECUTION_ERROR

EXECUTION_ERROR

Error message

Unknown error occurred

What it means

A non-Error, non-ZodError value was thrown inside remove_connection. The catch block emits 'Unknown error occurred' with code EXECUTION_ERROR because the thrown value has no .message. This signals a defect or unexpected rejection shape rather than a user-input problem.

Solutions

1. Inspect server logs around the tool invocation for the raw thrown value.
2. Reproduce with the same workflow JSON and connection coordinates.
3. Report as a bug with the workflow JSON, node names, and connection coordinates.

function isToolError(v: unknown): v is { message: string; code: string; details?: unknown } {
  return typeof v === 'object' && v !== null && 'code' in v && 'message' in v;
}

const res = await remove_connection.invoke(input);
if (isToolError(res) && res.code === 'EXECUTION_ERROR' && res.message === 'Unknown error occurred') {
  // defect path: log workflow JSON + connection coordinates, do not blindly retry
}

When it happens

Trigger: A helper throws a non-Error value; a promise rejects with a string/null; an internal invariant throws a literal.

Common situations: Bug in removeConnectionFromWorkflow state helper; race on workflow state access; unhandled edge case in connection array manipulation.

Related errors

• EXECUTION_ERROR
• EXECUTION_ERROR
• admittance_rejected
• Cannot call .input() on the workflow builder. Use .input()…
• Cannot call .output() on the workflow builder. Use…

AI-assisted analysis of n8n-io/n8n@5ac6606e81 (2026-08-12). Data as JSON: /api/errors/5cb926e05ea8479c. Report an issue: GitHub.

Appendix: source

Thrown at packages/@n8n/ai-workflow-builder.ee/src/tools/remove-connection.tool.ts:283

				return createSuccessResponse(config, message, stateUpdates);
			} catch (error) {
				// Handle validation or unexpected errors
				let toolError;

				if (error instanceof z.ZodError) {
					const validationError = new ValidationError('Invalid connection removal parameters', {
						field: error.errors[0]?.path.join('.'),
						value: error.errors[0]?.message,
					});
					toolError = {
						message: validationError.message,
						code: 'VALIDATION_ERROR',
						details: error.errors,
					};
				} else {
					toolError = {
						message: error instanceof Error ? error.message : 'Unknown error occurred',
						code: 'EXECUTION_ERROR',
					};
				}

				reporter.error(toolError);
				return createErrorResponse(config, toolError);
			}
		},
		{
			name: REMOVE_CONNECTION_TOOL.toolName,
			description: `Remove a specific connection between two nodes in the workflow. This allows you to disconnect nodes without deleting them.

USAGE:
Use this tool when you need to break an existing connection while keeping both nodes in the workflow.

PARAMETERS:
- sourceNodeId: The UUID of the node that is the source of the connection (where the data comes from)
- targetNodeId: The UUID of the node that receives the connection (where the data goes to)
- connectionType: The type of connection to remove (default: "main")

View on GitHub (pinned to 5ac6606e81)