react后端渲染关于方法react.renderToString的报错问题 求助

#1
Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in.

报错如上。我的代码如下:

    router.get('*', (req, res) => {
    // console.log(routes)

    match({ routes: routes, location: req.url }, (error, redirectLocation, renderProps) => {
        
        if (error) {
            res.send(500, error.message)
        } else if (redirectLocation) {
            res.redirect(302, redirectLocation.pathname + redirectLocation.search)
        } else if (renderProps) {
            console.log(renderToString(<RoutingContext {...renderProps} />));
        } else {
            res.send(404, 'Not found')
        }
        
    });
    
});

routes.js

    const routes = (
    <Route path="/" component={Home}/>
    
);
export default routes;