Have you run php artisan route:clear and do you see that route on the Larvel side?
Alternatively, if you are not using Laravel you could look to this to make sure the route is present:
import React from 'react';
import { Route, IndexRoute } from 'react-router';
import reactRouterToArray from 'react-router-to-array';
// or var reactRouterToArray = require('react-router-to-array');
console.log(reactRouterToArray(
<Route path="/" component={FakeComponent}>
{/* just to test comments */}
<IndexRoute component={FakeComponent} />
<Route path="about" component={FakeComponent}>
<Route path="home" component={FakeComponent} />
<Route path="/home/:userId" component={FakeComponent} />
</Route>
<Route path="users" component={FakeComponent} />
<Route path="*" component={FakeComponent} />
</Route>)
); //outputs: ['/', '/about', '/about/home', '/users']
You'd have to install react-router-to-array