Content.Error reads the form's validation and submission state and returns null when there is no message and no custom children.

<QuestionnaireForm.Content.Error style={{ color: "crimson" }} />

It renders a Paper Text with the error color. A custom children value replaces the translation lookup. Otherwise the component passes submissionError first, then errorMessage, to i18next; values that are not keys may be rendered unchanged by the active i18next configuration. When a submission error exists, it also renders a compact Try again button that calls the form's retrySubmit function. The component does not provide a dismiss action or an accessibility announcement by itself; add that behavior around it when your app requires it.

Validation messages are translation keys such as questionnaire-form.error.required-fields and, from the paged required-item guard, questionnaire-form.error.required (English default: This question is required). Submission errors may be backend/error strings. Supply matching i18n resources or pass custom children.