FlowiseAI/Flowise · error · Error

${e}

Error message

${e}

What it means

Top-level catch around executeJavaScriptCode in CustomDocumentLoader. It re-wraps any thrown value as new Error(e). If e is an Error, new Error(errorObject) calls errorObject.toString() so the original stack and name (SyntaxError, ReferenceError, etc.) are flattened into a generic Error message. This also re-wraps the [110] contract error, masking which check failed.

Source

Thrown at packages/components/nodes/documentloaders/CustomDocumentLoader/CustomDocumentLoader.ts:143

            if (output === 'document' && Array.isArray(response)) {
                if (response.length === 0) return response
                if (
                    response[0].pageContent &&
                    typeof response[0].pageContent === 'string' &&
                    response[0].metadata &&
                    typeof response[0].metadata === 'object'
                )
                    return response
                throw new Error('Document object must contain pageContent and metadata')
            }

            if (output === 'text' && typeof response === 'string') {
                return handleEscapeCharacters(response, false)
            }

            return response
        } catch (e) {
            throw new Error(e)
        }
    }
}

module.exports = { nodeClass: CustomDocumentLoader_DocumentLoaders }

View on GitHub (pinned to abe4a8601a)

Solutions

1. Read the message text carefully - it usually contains the underlying error string even though the type is lost.
2. If the message matches 'Document object must contain pageContent and metadata', the root cause is the shape contract (see error 110).
3. Wrap your sandbox body in its own try/catch and throw a descriptive Error so the outer wrapper has something useful to re-wrap.
4. Run the function body in Node with the same inputs to reproduce the underlying exception with its real stack.

Example fix

// before
} catch (e) {
  throw new Error(e)
}
// after - preserve the original error chain
} catch (e) {
  if (e instanceof Error) throw e
  throw new Error(typeof e === 'string' ? e : JSON.stringify(e))
}

function validateSandboxSource(fn: string): void {
  if (typeof fn !== 'string' || fn.trim() === '') throw new Error('javascriptFunction input is empty')
  // basic balance check to catch SyntaxError early
  const open = (fn.match(/[({[]/g) || []).length
  const close = (fn.match(/[)}\]]/g) || []).length
  if (open !== close) throw new Error(`javascriptFunction has unbalanced brackets: ${open} open vs ${close} close`)
}
// validateSandboxSource(nodeData.inputs?.javascriptFunction) before executeJavaScriptCode

function isErrorWithMessage(e: unknown): e is Error {
  return e instanceof Error || (typeof e === 'object' && e !== null && 'message' in e)
}

try {
  const result = await executeJavaScriptCode(javascriptFunction, sandbox, { libraries: ['axios'] })
  return result
} catch (e) {
  // The outer wrapper flattens e to a string message; parse it back
  const msg = e instanceof Error ? e.message : String(e)
  if (/is not defined/.test(msg)) throw new Error(`Sandbox ReferenceError: ${msg}. Allowed vars: input, $<inputVars>, flow, vars.`)
  throw e
}

When it happens

Trigger: Sandbox function threw a ReferenceError (undefined variable), SyntaxError (bad JS), TypeError, or timed out; the contract check at [110] threw and was re-caught here.

Common situations: User code has a typo or references an undefined sandbox variable; the function references a library not in the allowed list (['axios']); an exception from the document-shape check gets flattened so the user sees only 'Error: ...'.

Related errors

• Document object must contain pageContent and metadata
• ${e}
• ${e}
• ${e}
• Failed to fetch ${url} from Airtable: ${error}

AI-assisted analysis of FlowiseAI/Flowise@abe4a8601a (2026-08-12). Data as JSON: /api/errors/9c8477cde2450015. Report an issue: GitHub.