octobercms/october · error · SystemException

Form behavior does not contain a field for ':field'.

Error message

Form behavior does not contain a field for ':field'.

What it means

Error "Form behavior does not contain a field for ':field'." thrown in octobercms/october.

Source

Thrown at modules/backend/widgets/Form.php:319

    /**
     * renderField renders a single form field
     *
     * Options:
     *  - useContainer: Wrap the result in a container, used by AJAX. Default: true
     *
     * @param \Backend\Classes\FormField|string $field The field name or definition
     * @param array $options
     * @return string|bool The rendered partial contents, or false if suppressing an exception
     */
    public function renderField($field, $options = [])
    {
        $this->defineFormFields();
        $this->prepareVars();

        if (is_string($field)) {
            if (!isset($this->allFields[$field])) {
                throw new SystemException(Lang::get(
                    'backend::lang.form.missing_definition',
                    compact('field')
                ));
            }

            $field = $this->allFields[$field];
        }

        if (!isset($options['useContainer'])) {
            $options['useContainer'] = true;
        }

        $targetPartial = $options['useContainer'] ? 'field-container' : 'field';

        return $this->makePartial($targetPartial, ['field' => $field]);
    }

    /**

View on GitHub (pinned to b608633a7e)

When it happens

Trigger: Thrown at modules/backend/widgets/Form.php:319 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of octobercms/october@b608633a7e (2026-08-21). Data as JSON: /api/errors/33295a200ed2b3bc. Report an issue: GitHub.