marmelab/react-admin · error

Label parameter must be a string, a ReactElement or false

Error message

Label parameter must be a string, a ReactElement or false

What it means

FieldTitle computes a field's label from the label/source props and translation. The `label` prop may be a string, a ReactElement, or false; passing `true` is invalid because there is no meaningful rendering for a boolean true label, so it throws immediately.

Source

Thrown at packages/ra-core/src/util/FieldTitle.tsx:18

import * as React from 'react';
import { ReactNode, memo } from 'react';

import { useTranslateLabel } from '../i18n';

export interface FieldTitleProps {
    isRequired?: boolean;
    resource?: string;
    source?: string;
    label?: ReactNode;
}

export const FieldTitle = (props: FieldTitleProps) => {
    const { source, label, resource, isRequired } = props;
    const translateLabel = useTranslateLabel();

    if (label === true) {
        throw new Error(
            'Label parameter must be a string, a ReactElement or false'
        );
    }

    if (label === false || label === '') {
        return null;
    }

    if (label != null && typeof label !== 'string') {
        return label;
    }

    return (
        <span>
            {translateLabel({
                label,
                resource,
                source,

View on GitHub (pinned to 051f511bb0)

Solutions

1. Remove the label prop entirely to use the default (translated from source)
2. Pass a concrete string: label="My label" or a translation element <label={<Translate i18nKey="..." />} />
3. Pass label={false} to hide the label
4. Fix the upstream value so booleans never reach label (coerce at the config boundary)

Example fix

// before
<TextInput source="name" label={showLabel} />

// after
<TextInput source="name" label={showLabel ? 'Name' : false} />

const VALID = (v) => v === false || typeof v === 'string' || React.isValidElement(v) || v == null;
if (label != null && !VALID(label)) throw new Error('label must be string, element, or false');

const isValidLabel = (label: unknown): label is string | React.ReactElement | false | undefined =>
  label === false || label === undefined || typeof label === 'string' || React.isValidElement(label);

try {
  setLabel(config.label);
} catch (e) {
  if (e.message.includes('Label parameter must be')) {
    setLabel(undefined); // fall back to default label
  } else throw e;
}

When it happens

Trigger: Passing label={true} (or a variable evaluating to true) to an input or field such as <TextInput source="x" label={true} />; spreading props where label came from untyped config/JSON containing true; TypeScript bypassed with `any` so the union type didn't catch it.

Common situations: Dynamic label configuration from backend/CMS values; conditional label logic like label={someCondition} that resolves to a boolean; migrating code where label was previously optional and someone used true as 'show label'.

Related errors

• useCreate mutation requires a resource
• useCreate mutation requires a non-empty data object
• useDelete mutation requires a resource
• useDelete mutation requires a non-empty id
• useDeleteMany mutation requires a resource

AI-assisted analysis of marmelab/react-admin@051f511bb0 (2026-08-30). Data as JSON: /api/errors/228e073a0ac32c61. Report an issue: GitHub.