Final Class Yiisoft\Widget\NotInstantiableException

                public function __construct(
    private string $widgetClassName,
    private bool $widgetFactoryInitialized,
    private Throwable $previous,
) {
    $message = 'Failed to create a widget "' . $this->widgetClassName . '". ' . $previous->getMessage();
    if (!$this->widgetFactoryInitialized) {
        $message .= ' Perhaps you need to initialize "' . WidgetFactory::class . '" with DI container to resolve dependencies.';
    }
    parent::__construct($message, previous: $previous);
}

            

                public function getName(): string
{
    return 'Failed to create a widget "' . $this->widgetClassName . '". ' . $this->previous->getMessage();
}

            

                public function getSolution(): ?string
{
    if ($this->widgetFactoryInitialized) {
        return null;
    }
    $widgetFactoryClass = WidgetFactory::class;
    return <<<SOLUTION
        Perhaps you need to initialize "$widgetFactoryClass" with DI container to resolve dependencies.
        To initialize the widget factory call `WidgetFactory::initialize()` before using the widget.
        It is a good idea to do that for the whole application.
        Example:
        ```php
        /**
         * @var Psr\Container\ContainerInterface \$container
         */
        Yiisoft\Widget\WidgetFactory::initialize(
            container: \$container,
            definitions: [MyWidget::class => new MyWidget(/*...*/)],
            themes: [
                'custom' => [
                    MyWidget::class => [
                        'setValue()' => [42],
                    ],
                ],
            ],
            validate: true, // Whether definitions need to be validated.
        );
        ```
        See Yii example in the configuration file of this package `config/bootstrap.php`.
        SOLUTION;
}