When I quick save twice in hmr environment , it will throw this error.

![wrong imgae](https://i.stack.imgur.com/iFzFG.png)

it lead this way =>

```js
var hmrBootstrap = function (module, bootstrap) {
    var ngModule;
    module.hot.accept();
    bootstrap().then(function (mod) { return ngModule = mod; });
    module.hot.dispose(function () {
        var appRef = ngModule.injector.get(_angular_core__WEBPACK_IMPORTED_MODULE_0__["ApplicationRef"]);
        var elements = appRef.components.map(function (c) { return c.location.nativeElement; });
        var makeVisible = Object(_angularclass_hmr__WEBPACK_IMPORTED_MODULE_1__["createNewHosts"])(elements);
        ngModule.destroy();
        makeVisible();
    });
};

```

and there is part of my main.ts:

```js
import { hmrBootstrap } from 'hmr';

if (environment.production) {
  enableProdMode();
}

const bootstrap = () => platformBrowserDynamic().bootstrapModule(AppModule);

if (environment.hmr) {
  if (module[ 'hot' ]) {
    hmrBootstrap(module, bootstrap);
  } else {
    console.error('HMR is not enabled for webpack-dev-server!');
    console.log('Are you using the --hmr flag for ng serve?');
  }
} else {
  bootstrap().catch(err => console.log(err));
}

```

i don't know where is wrong, if you can help me. thank you very much!